This was no attempt to destroy Ukraine. That you’ll not benefit Russia. It was a control device to make the world know any attempt by any country to block access to the Black Sea would result in a war the Ukraine would not survive even with NATO support if they could get it. This is Russia using Ukraine like a political football… just a safety not a field goal or touchdown.. Russia has to much to gain by keeping the Ukraine as an asset.
Look at the map. Russia had Crimea before the war, and even if it didn't, it still would have other ports in the black sea. So what you're saying is utter bullshit. On the other hand, Russia in this war is clearly attempting to take the entire Ukrainian coastline from sea of Azov to Odessa (although the latter plan may have been delayed or abandoned due to Ukrainian resistance), thereby blocking
Ukraine's access to the black sea.
Like all pro-Russian apologists, or idiots who believe Russian propaganda, you're blaming Ukraine for the things that Russia is actually doing.