(Note: throughout, I assume we're only discussing post-Resurrection sightings.)
There are at least five symmetry breakers (for the sake of making this Answer as complete as possible, I am shamelessly stealing two from vsz's Answer to add to my original three):
Bigfoot sightings are less reliable.
Bigfoot sightings seldom have high quality concrete evidence associated with them, and are often debunked. Such "sightings" also often consist of a brief and obscured glance. "Jesus sightings" weren't just sightings; people touched Him, spoke with Him, and ate with Him over sustained periods of time. The difference is thinking you saw Stan Lee out of the corner of your eye versus sitting down and eating a meal with Stan Lee. Contemporary opponents also lack a documented history of being able to refute such sightings.
Another point is that bigfoot sightings rarely involve more than one person at a time. On at least one occasion, Jesus was seen by hundreds of people at once.
(Corollary) Bigfoot sightings are "easier".
Having noted that most sightings are based on evidence of questionable reliability, it follows that it takes less evidence to produce a "sighting". As a result, we would naturally expect the number of sightings to be higher, since the set of "Jesus sightings" to which we're comparing doesn't include everyone that only thought they caught a glimpse of Jesus.
Additionally, the existence of the "bigfoot meme" likely leads to a certain predisposition to interpreting something unfamiliar as a "bigfoot"; that is, there is some subconscious expectation that one might see a "bigfoot". By contrast, the early disciples didn't expect to see a Resurrected Jesus, as evidences by their initial exhibition of fear and despair. Indeed, one of the earliest sightings mistook Jesus for a gardener!
It should be mentioned that there are contemporary claims of people seeing Jesus (albeit not as a corporeal entity). If these are included, the ratio of sightings improves significantly. However, these are subject to similar potential issues and are therefore less reliable that the testimonies recorded in Scripture. Additionally, if one is arguing in terms of number of sightings, these latter sightings seem to be implicitly excluded.
For more on extra-biblical reports of "Jesus sightings", see Christophany.
Bigfoot sightings are more temporally sparse.
I don't have exact data handy, but the Question mentions 1970 and 2019, which indicates that bigfoot sightings have taken place over at least fifty years.
With one exception (Paul on the road to Damascus), "Jesus sightings" took place over only forty days. Many sightings are recorded during this time, including, as previously mentioned, one involving a large number of people at once. Given that the window of opportunity for "Jesus sightings" to occur was small, the temporal density is significantly higher.
Bigfoot sightings are incentivized.
Contemporary "bigfoot sightings" are a plausible way for some random individual to "get their fifteen minutes of fame". Many people are interested in "bigfoot sightings" and will give special attention to those claiming to have had one. (This is also true for extraterrestrial sightings.) In other words, there is an incentive to fraudulently create such claims, and little negative consequence to promoting such a claim. Additionally, even a claim that isn't consciously fraudulent might be influenced by a desire to have such an experience.
By contrast, the consequences for "Jesus sightings" were persecution, torture and death. If anything, you'd expect this to mean that people would keep quiet about "Jesus sightings", especially if they have any doubt about what they actually saw, or at the very least to recant when faced with torture and execution. The number of witnesses that didn't is a clear exposition that these people were both confident in what they saw, and confident of the significance of what they saw.
There are more people alive today, and communication is easier.
Another point to keep in mind is that there are simply more people alive today. If we say "X sightings are more reliable than Y sightings, because X has ten times as many reports", is that really true if the population of people that might have seen X is a hundred times the number of people that might have seen Y?
The current US population is about 300 million people. Accounting for tourism and deaths in the last fifty years, there are perhaps 500 million people who have the potential to experience a bigfoot sighting. It's difficult to estimate the number of potential "Jesus sightings", but 10 million seems to be a very generous estimate.
Another point is that it is incredibly easy these days for any crackpot to reach an audience simply by posting something on the internet. Even fifty years ago, communication technology was vastly superior to that which existed in the first century AD. Therefore, it's much easier for unreliable sightings to be reported. By comparison, it's not inconceivable that thousands of "Jesus sightings" occurred but were not recorded, or that such records are lost to time.
Let's keep playing...
Simply put, if this argument is valid, then the evidence that extraterrestrials exists is much stronger than the evidence for the existence of a great many historical figures from the time of Christ and earlier. Yet the existence of said persons is rarely the subject of serious doubt, while the existence of extraterrestrials is met with much skepticism.
The difference when it comes to Christ is that His (post-Crucifixion) existence raises uncomfortable questions about the nature of reality, and in particular, the existence of a supreme being (God) and one's potential accountability to the same. The problem isn't that the evidence is poor, it's that the philosophical implications are objectionable.
Bigfoot sightings aren't "more direct".
While not precisely a "symmetry breaker" in the manner of the above, the objection has also been raised that "Jesus sightings" are substantially hearsay ("it's quite likely that what we have is not even reports of reports, but reports of reports of reports of reports"). This is simply false. The Gospel of John was written (possibly, dictated) by the Apostle John, who was an eyewitness to at least two of the post-Resurrection appearances. Acts, and the Gospel of Luke, were written by Luke based on eyewitness testimony. Additionally, while Luke was not one of the twelve apostles, it is possible he was an eyewitness to one or more post-Resurrection appearances, particularly the one in which Jesus "appeared to more than five hundred brothers at one time" (1 Corinthians 15:6).
By comparison, while some may be "eyewitness testimony", most "bigfoot sightings", in the form one actually encounters them, are likely to be one or more times repeated. Thus, there is no practical difference here.
Attacking the authorship is a favorite technique of those who wish to deny the authenticity of Scripture, but it is not one which is rationally justified.