I propose at least 5 reasons for this to be the case:
1. Seek the best gifts
In 1 Cor 12:31 Paul counsels people to desire/covet/zealously strive for the best gifts. The seeking & zeal imply action on the believer's part; believers are not instructed to sit back, relax, and wait for God to deliver gifts with 2-day shipping (tracking number included). Jesus taught people to ask, seek, and knock. Apparently some blessings are given contingent upon asking for them (in faith) and contributing one's own best--albeit meager--efforts.
When we consider the intense labor & trial Paul was called upon to endure in order to convey the gospel with spiritual power (e.g. see 1 Cor. 2:4), why should we expect otherwise?
2. Diversity of Gifts
Paul's comparison of the faithful to hands, feet, noses, etc.--each essential although performing different functions--presupposes that not every gift is given to every believer--the analogy falls apart otherwise. We should not expect every gift to be demonstrated in every individual, but that the collective gifts/strengths individuals bring to the work accomplishes what no single individual could do.
Nowhere do the scriptural texts on gifts suggest that they have provided a finite list of all possible gifts...indeed, the fact that the lists given in different passages are not identical requires that the individual lists are not intended to be exhaustive. There is no Biblical basis for concluding that if a gift is not enumerated in the Bible it cannot come from God.
3. Purpose of miracles
What is the purpose of miracles?
John 6:66 makes it pretty clear that miracles are not the secret sauce to conversion, and that God doesn't just want people's curiosity, He wants their heart.
I suggest that God performs miracles to aid His children in accomplishing what they otherwise could not do on their own, not to show off. If the goal of miracles were to impress people into believing, God could just show Himself to everyone with thunder & lightning. Jesus could have just appeared to everyone in Jerusalem after the resurrection. God could solve every problem in the way people desire immediately upon request. This is not God's plan or program - He wants to change people, not merely ooh and aah them like a stage performer.
I share further thoughts on why God deliberately does not appear to everyone on my channel here.
(additionally, if God is supplying miraculous aid to do for us what we cannot do for ourselves, one would expect that miraculous healings would decrease in frequency at least a little bit as medical knowledge advances...it wouldn't be particularly consistent for someone to plead to God for healing while denying readily available aid that He has inspired. Cue the cliché about the man dying in a flood after God sends a boat, helicopter, etc. to rescue him and he turns them all down)
For believers in the Great Apostasy, such as myself, the unsavory realities described by Paul in 2 Tim. 3:1-7, 2 Thess. 2:3, etc. suggest a time where the gifts & power of God would be less evident in many people's lives. Indeed as recently as the 19th century it was commonplace among many Christians to believe that:
there were no such things as visions or revelations in these days; that all such things had ceased with the apostles, and that there would never be any more of them. (source -- note that I am quoting what others have said, this statement does not at all reflect my personal beliefs)
This viewpoint clearly depicts a time when people are less likely to expect gifts from God, less likely to ask for them, and less likely to attribute divine aid in their lives to God when it does come.
Mark 16 teaches that "signs shall follow them that believe" (not "them that believe shall follow signs"). If there is a decline in belief, access to truth, authority & power from God, or other features often associated with apostasy, a decrease in frequency of signs should not be surprising.
5. Sacred nature of divine experiences
- John is the only evangelist who does not write about the mount of transfiguration, even though he was the only one of the four who was present.
- Mary had sacred experiences--surely most of which we know nothing about--and yet it is said of her:
But Mary kept all these things, and pondered them in her heart. (Luke 2:19)
- Jesus taught that we should not cast our pearls before swine. If people choose to mock belief in miracles reported in the past, why would they be any less condescending towards miracles reported in the present? What good would come of tossing a few more pearls in their path? (see also Jesus' excellent summary of this reality in Luke 16:31, and His teaching in Luke 12:47-48 for why it is merciful to not give people light & truth they aren't ready for).
I suggest there is little to be gained in sharing deeply personal, private experiences in impersonal, public ways, unless instructed by God to do otherwise. A powerful spiritual manifestation cannot be adequately represented by the clumsy, imprecise symbols we call words. As a result, many believers will point people directly to the source, rather than trying to impress people by showing off their own blessings.
I am aware of modern examples of all of the miraculous phenomena described in the OP. A public internet forum is not the place to share them. (Alas, this means that there is a chronic, statistical underreporting of miracles on the internet).
While God does show a pattern of validating--through demonstrations of His power--the authenticity of the call of His servants who are asked to open a new chapter/covenant/dispensation of His work (think Enoch, Noah, Abraham, Moses, etc.)--it is my experience that most of the miraculous gifts God gives to the faithful are private, personal experiences, designed to convert & develop the believer and aid them in doing His work, not to score headlines.
It is not my place to question the sincerity of anyone else's convictions. But it is my experience that when people diligently & sincerely apply Jesus' command to ask, seek, and knock, God gives knowledge & power in miraculous ways.
These gifts from God may not always be dazzling, and they may not ever be publicly known, but as impressive as moving a mountain may be, I propose that a far greater miracle is performed every time God changes a person's heart.