Only a fraction of the currently active troops in Ukraine have received training from NATO, only a fraction are armed with NATO weaponry, and Ukraine hasn’t received significant amounts of aircraft, which is the linchpin to the entire NATO offensive strategy.
So if Russia is struggling to make the progress it has against a force that ISN’T fully armed with NATO weaponry and strategy, it stands to reason they would fare even worse against NATO itself.
The rest of your post is lot of words without much of a point. So Russia should be allowed to invade Ukraine and commit atrocities against their people because… the United States did bad things in the past? But if its awful when the United States does it why would you support Russia also doing it?