Well, by all accounts (and I'd love to read others that diverge from this) this was actually Russia's exact strategy. Move to Kyiv quickly, destroy the existing government, install a new puppet government, and announce it to the world quickly before the west could react. Russia doesn't have the manpower deployed to actually occupy Ukraine. 200,000 soldiers is not enough when the Ukrainian state is actively resisting. This is why they tried some absolutely suicidal paratrooper missions and they are having all of these apparent logistical issues (again if there are other sources I'd like to learn more please share).

I think if I were to summarize the "Russia is failing" narrative it's that Russia expectations of a quick, easy victory were completely unmet, and now even if Russia does want to occupy Ukraine it's not going to be the quick and easy decapitation strike that they thought it would.