I mean, in the whole buildup to the Ukraine invasion, I just keep thinking "what is the purpose of this?" I've read tons of background articles about the Russia/Ukraine conflict, and I have a pretty good understanding of Russian-Ukrainian history that is not often presented in Western media (e.g. the history of Crimea in the 20th century). But literally none of that points to a logical reason for this invasion, of this scope, now:
1. Russia is upset about the expansion of NATO. A very fair point, but the last expansion of Nato that Russia really had a reason to be mad about happened in 2004. Ukraine isn't really any closer to being a NATO member now than 10 years ago.
2. Protection of separatists in the Donbas region. Even if you did buy all of the Russian propaganda about what's going on in Donbas, in that case I could at least see an argument for annexing Luhansk and Donetsk, but not invading the whole country.
3. Keeping Ukraine within the Russian "sphere of influence". Again, I can understand the rationale for Russia wanting to do this, but I see invasion as extremely counterproductive to that goal.
Honestly, I see a ton of parallels with the 2003 US invasion of Iraq. The invasion of Afghanistan after 9/11 at least made sense to me from the perspective of having a purpose; I remember the rush to war in Iraq in 2003 and the whole thing just seemed really stupid to me, like "well, we attacked one country, we're not done yet, so we have to find another country to invade." Similarly, while perhaps an unpopular viewpoint in the West, I understood the rationale behind annexing Crimea, but the invasion of Ukraine just leads me to believe "all outcomes will be bad, for Russia".
It's just good to remember that many times war happens for really, really dumb reasons.