Well, such approach to foreign policy (if destroying a nation just to mess with a third party can be called that) certainly backfired, as now historically neutral nations want to join NATO.
Ukraine's position and the geostrategic significance of its border makes it joining NATO an existential threat to Russia.
Sweden and Finland do not pose such a threat. Finland is on the border too but a much less exposed portion.
The costs of this invasion were clear from the outset. Russia isnt going into this thinking it will come out stronger and ready to conquer the world. It's a fairly desperate and high stakes ploy to shield their jugular.
How does NATO pose an existential threat to Russia? There would only be a conflict between them if Russia attacked a NATO country. Is existential for Russia to invade and attack neighbors? We might be upon a r/SelfAwareWolves moment.
This is more a nationalist Russkiy Mir/Russkaya Zemlya kind of mental jerk, as evidenced by that article that RIA Novosti published (and then pulled)[0]: if they don't take now what they consider theirs(Ukraine), then they never will if they join NATO. To have one people split in two (though Ukrainians largely disagree) is unacceptable to them.
It does though. Latest Putin demands involve complete demilitarization of Ukraine. For what purpose? Invading it better afterwards?