From a Biblical Unitarian perspective - those that hold scripture as being wholly sufficient to reveal all truth about God, His son Jesus the Christ and His salvation plan for man made possible through him.
How do those who believe that Jesus is a created being understand the verses which say everything that was created was created by him? We'll examine the verses to see if they mean what OP suggests they do.
Everything became through the word, and without the word did not become one that has become. John 1:3
This verse was quoted as a proof that Jesus is not created. Does it say Jesus? No, it doesn't - it speaks of the 'word' or 'logos' Gr.
When did Jesus enter the biblical narrative? When the logos became flesh.
When was that? as John records in v14 (~4BC) Jesus is simply not mentioned anywhere until this point of his conception in Mary and subsequent birth. Equally, there is no 'Holy Son' mentioned either except in the form of a man who would fulfil various prophecies.
There is no need to add imaginative and special reading into the text. If it says 'logos' it is not saying Jesus. Jesus IS the logos, but only after it became flesh. We can see from 1John 1, John expresses this logos as a 'which' - not as a who or person until manifested in Jesus at his conception.
From this careful reading of the text, we see that Jesus was not 'in the beginning', but the logos was. And with God, which also means not God as God is God.
Colossians 1:15-16 (NIV): The Son is the image of the invisible God, the firstborn over all creation. For in him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things have been created through him and for him.
The context is again, vitally important. Is Paul speaking of a Genesis creation as we read in Genesis 1? No. The context is the new creation, the church, the fact that all God's work in making man would be realised fully in, and only in, Christ. Without Christ - who is the image of God, we cannot be the image of God either. All things are fully realised in this new age in Christ. (Rom 8:29) Same story for Romans 11:36 as OP quoted.
A traditional approach proposes Jesus was somehow born from all eternity. By reading the text carefully we remove the need to make careless assumptions. Note Col 1 carefully, "things in heaven and on earth". God created the earth and the heavens - not just the things ON the earth or IN the heavens. Again, this is not speaking of a Genesis creation so we cannot carelessly insert Jesus into it without creating massive contradictions within scripture.
The OP states, "I mean, that's pretty obvious." (That all was created through Jesus). We might think this but only if we read in that which is not there and fill any gaps we perceive from a faulty premise. Jesus didn't create anything. He is the servant of the Creator, not the Creator. Just as the logos did not create either, but God created 'through' His logos.
He received the spirit from God - making him again - not God.
Here is My servant, whom I have chosen, My beloved, in whom My soul delights. I will put My spirit on him, and he will proclaim justice to the nations. Matt 12:18 (Luke 3:22)
In attempting reconcile these obvious truths about Jesus not being God, a "two-natured" Jesus was devised. That way he can be a man when he needs to be - like be tempted and die, to be flesh and not spirit, to be made heir and exalted to the heavens. And be a God when he needs to be to fit other dogma. This concept is not biblical but a distraction from the biblical truth of the human Jesus, born of Mary with no pre-existence, made like us in every way Heb 2:17 If he is also God - he is not like us at all!
Extracts from; https://www.biblicalunitarian.com/ https://www.biblicalunitarian.com/verses