The geogrpahy of Ukraine is one of the only flat plains areas of Russia's borders and land, it is one of the easiest parts to expand into almost all Russian land, it is part of why the wars with Russia typically went through that area, or majorly focused on pushes from it. The lands surrounding and behind Ukraine are mountains, swamps, hilly forests and so on, they are at worst not hundreds of kilomtres of generally easily traversed open ground. Russia has a resource shortage, but also, has a profit incentive with materials. Their economy is currently collapsing and a lot of it is to do with how many assets they lost with the USSR split + bad management on top. They also have resources that Russia was entirely reliant on - manpower, urban production and agriculture. There is pretty much nowhere else n their lands that is suitable, but, they lost a chunk of manpower they still have not recovered yet, and they also lost a major centre of industrial power, given how many factories, raw ores, smelters and so on, they would have lost. The food situation is truly the most appalling one, Ukraine was basically the lifeblood, in terms of food, for the entire entity. It has the most fertile lands, most suitable ones, and now that it is gone, the majority productions have shifted, and their total production has gone down massively. Things like fishing now dominate their markets, alongside pretty harsh exports. They could be peaceful, and slowly collapse as a nation, most likely endure famine and depressions, they would be lucky if they did not. Or, they could invade countries that seceded from them. It really is not the most morally confusing or irrational choice. Whether you agree with it, or think it was the best choice, is not really the point. The point is that it makes sense. I think what Russia is doing is far from their best interest, and things could have been done much better, but it is nowhere near completely senseless. Russia's future literally depends on this. Did.
Possible stationing of troops in unfavourable territory, hard to repulse an invasion into the more Western parts of Ukraine, but very easy to get through the Eastern parts, giving them and anyone else a rather significant advantage, especially in much larger conflicts, it is rather close to the heartland of Russia, missile arrays ands so on, it makes their naval capacity and control rather restricted, in an already restricted situation, and easily cut off. It is a huge centre for logistics, which means the possibility of quickly expanding and supporting an invasion is very high. (Just to elaborate on why it is so strategically worrying).
Ukraine can be justified in defending itself, but that does not mean Russia has to be completely maniacal in attacking.
Life is not really as convenient as 'the good guys' v 'the bad guys'
A second Holodomor would defeat the point of invading the,, especially because the Holodomor was, as far as I know, the result of unfortunate circumstances and severely lacking administration and rationality on the part of the USSR. But I digress.