No they have not. It is why I said that for them to lose politically Ukraine has to be admitted to NATO, or Russia will have to be militarily defeated, which does not look likely.
What you are talking about is political legitimacy and that does not matter, because that negative opinion about Russia is only held amongst one half of the population in North America and Europe.
Ukraine was already not in NATO and no one thought they would be likely admitted to NATO in the near future.
The attack made that admission more likely.
So even if you limit the political objective to "Keep Ukraine out of NATO" this looks like a loser. (More of a loser if you take it as "curb NATO expansion" since it led directly to Sweden and Finland joining.)
The political legitimacy question
does matter and it matters to Russia a lot.
It isn't about "Do people like us" it is about "Do they have to treat us like a major power".
Russia getting in this mess has reduced its standing internationally. Countries that would have been afraid to piss it off are willing to do so now. Countries that thought it's military could crush them in days no longer believe that. Perception matters, and managing that perception is important to the Putin regime. (It is important to
most regimes.)
"We told you we wouldn't accept this, we walked in and took over Ukraine in 3 days because you didn't listen" sends a message to the world.
Trying that and failing sends a different one.