I think a LOT of people are being SUPER myopic about Russian aggression.

Sure, taking ground, flexing power, etc.

But look at the bigger picture.

Ukraine is a NATO country as of 2020. They are also part of the EU as of 2016.

In 2020, Trump lost an election and Angela Merkel retired. This provides opportunity. Since ancient times, leadership transitions have always been opportunities for enemies.

Right now, what does Russia have to gain even from appearing aggressive?

Well, the EU, NATO, and the US all have other stuff going on. The EU and US are both struggling to shift course on environmental issues. Both have unity issues. Both have right wing and fascism on the rise. Destabilization is hard to handle in the best of times, but what if their leadership is dealing with an external crisis too?

Russia's actions distract and create problems. Even if Russia were to do nothing, Biden, NATO, and the EU HAVE to spend both time and resources in response. This uses up money and bandwidth they need to deal with internal problems.

Imagine you're trying to deal with a difficult math problem, but as you are working, your friend sitting next to your keeps getting poked from behind by the asshole in the classroom. Over and over, your friend keeps complaining, says that shit hurts. It's going to distract you enough that you aren't going to do as well on your math test.

The bully might just be an asshole picking on your friend so later he can steal his lunch, but maybe he ALSO knows it'll fuck with you at the same time.