Crimea is actually super strategic point, if you look at history of Russia. Whomever controls it, control several trade routes including the main Russian river trade route, and also have good chance to control Black Sea. You can see a lot of countries vying for power there - from Byzantium through Crimean Tatars, Turkey to Russia. And for Russia it is the most significant trade route even today - if you ever wondered why Russian Empire wanted Constantinople and USSR pressed Turkey for neutrality it was precisely to secure this route.

So when USSR was destroyed and Crimea ended up in Ukraine, Russia found itself potentially cut off from Black Sea militarily, thus without option to actually secure its own main trade route. That's why they secured the lease of the port of Sevastopol, but it was half measure, as became evident in 2014, one of the main reasons of USA supporting that coup was to annul that lease and kick off Russian Navy from Black Sea which would allow easy grabbing Russia by the balls economically. Russia obviously was prepared for that and they immediately pushed for the annexation.

So, @SpaceDogs@lemmygrad.ml Zelensky probably don't give a shit, but his CIA handlers do.