I'm going to address the second part of ^ this reply later. Because that's something you have gotten so terribly wrong. For now, I'm just going to answer the first part.
Sin is a transgression of God’s law. It's rebellion against God. Like young children or babies, animals do not have the same capacity we have to understand concepts like sin. Therefore, they are not held to the same standard that we are, as humans above the age of accountability.
Secondly, it was humans, not animals, who chose to rebel against God in the first place. If you want scriptures, we can start with Romans 5:12. “Therefore, just as sin came into the world through one man…” No mention of animals there.
Unfortunately, all of creation was affected by our choice to disobey God:
For the creation was subjected to futility, not willingly, but because of him who subjected it, in hope that the creation itself will be set free from its bondage to corruption and obtain the freedom of the glory of the children of God. For we know that the whole creation has been groaning together in the pains of childbirth until now.
Romans 8:20-22
To sum this up, animals didn’t sin, we did. Animals are not considered to be moral agents.
Like young children or babies, animals are innocent.
And honestly, the more I think and learn about this topic, the more abhorrent this world looks to me, because what we as human beings have done is reprehensible.
We have betrayed the most innocent among us, who trust us and who look to us to take care of them. Instead of taking care of them and loving them, we BETRAY them, exploit them, harm, abuse, torture, and needlessly kill them, for our own interests. That is the exact opposite of what we were supposed to do!
Make no mistake. The Bible is clear that when Jesus comes back, in the age to come, the violence and cruelty of this world will be a thing of the past. Are you ready for that? I'm not singling you out, but the reason I ask is because like most people, you seem to prefer the status quo of this fallen world, at least as it pertains to carnism and the topic of animals. As Christians, we are taught to prepared for what is to come, like the wise virgins were in that parable, and that is just one example of the teaching that we should be ready for the future instead of opposing it.
According to the Bible, here is the future:
The wolf will live with the lamb,
and the leopard will lie down with the goat.
The calf, the young lion, and the fatling will be together,
and a child will lead them.
The cow and the bear will graze,
their young ones will lie down together,
and the lion will eat straw like the ox.
An infant will play beside the cobra’s pit,
and a toddler will put his hand into a snake’s den.
None will harm or destroy another
on My entire holy mountain,
for the land will be as full
of the knowledge of the Lord
as the sea is filled with water.
Isaiah 11:6-9