If air supremacy is established tanks and static artillery become useless. They are sitting ducks.
I am pretty perplexed with what is happening with the Russian armed forces. They seem to be suffering from poor planning, indecision, and poorly maintained equipment.
It as if Putin drafted rough plans to attack, but never finalized them. Then, after all that public grandstanding he couldn’t back down without looking like a coward. So he said “fuck it”, and gambled hoping it would be Crimea 2.0.
We didn’t stand up enough to him then, so the bully got emboldened.
Take that with a grain of salt. If you research the history of Russian conflicts, stating that they were told it was just training is a common trope of captured Russians (https://news.ycombinator.com/item?id=30549427). It's basically a survival technique. Don't underestimate the indoctrination apparatus of the Russian army. They were sent there to kill, and they know it. Imagine being in 'training' and seeing medical tents + doctors + blood supplies. Give me a break. That doesn't rule out poor planning and/or poor logistics..