You're right, people don't think about these things from a more open perspective.
A general rule of thumb I follow is if someone who is otherwise successful, particular for a prolonged period of time, is doing something that is purportedly crazy, stupid, reckless, etc, I ask myself if maybe I haven't fully considered the situation.
Even if one falls into the camp of Putin being evil incarnate, he's been evil incarnate in power for quite a while and has presided over a Russia that by almost any metric is vastly improved relative to when he came into power. Whatever you say, Putin is not crazy and he's not stupid.
Maybe, just maybe, Russia found herself in a situation where very severe sanctions and being decoupled from the west, an area they tried tirelessly to forge ties with vis a vis energy, etc, maybe they found themselves in a situation where as bad as that outcome was, not invading Ukraine would be worse. Why might that be? They may be wrong, but more likely than not, this was a choice arrived at reluctantly and from their perspective, all the other options were _worse_ than potential war with the entirety of the collective west, deaths of tens of thousands, etc, etc.
I find that when I think of the actions of powerful nations and people as driven by a coherent thought process, I'm better able to predict their actions. I often think these entities may be wrong, that they may misunderstand some other process themselves, that they may be motivated by internal political considerations, etc, but it's never the cartoon version we hear in the media.
It's strange that people so rarely exercise this kind of thought. Do they still do those exercises in school where one has to argue both sides of a contentious issue? It's an essential skill.