I have to differ, specifically on the part 'nobody wants it to happen.' That's true for 99% of everyone in Western Europe, but Putin is clearly set to achieve something. He dare not withdraw those troops without getting something from NATO, it will be political suicide for his image, and they made it clear they won't concede to his public demands. So what's he to do? 

Personally I think he's aiming to get at least a part of Ukraine to become permanent Russian territory, specifically the Donbas region with its majority Russian speakers living there. It's a coal-rich area, and China's energy needs are under severe strain. So, coal for China, and China helps Russia circumvent the expected SWIFT sanctions, while Putin cut his gas pipelines supplying 40% of Western Europe for 3 months as leverage. The latter will politically destabilize Europe where elections are underway (like France, with its many industrial strikes), which is something both Russia and China like.

 Putin is a master at politics, and he plays the divided West like a fiddle. 🤣 He does not care about losing his pawns (soldiers) to accomplish goals, and a war will boost his waning popularity in Russia, and emergency measures will solidify his autocratic hold even more. 

His government is running propaganda full-steam everywhere in Russia now, with even television channels saying that MAD is outdated, Russia will win a nuclear war. Putin won't pull off such major gambles without having a big goal in mind.