If Russian forces have good number of UAVs for both sensors and attack, and good number of guided munitions, the troop numbers wouldn't matter as much. The Ukrainian supplies would have been cut and every bunker, pillbox, trenches outside of cities bombed.
I get what you are saying and I don't disagree with you (same reason why I dont view the "50000 shells per day" claim as that much of a positive for showing Russia's military strength).
However Ukraine is a huge country, even with all the high tech on the world, best ISR platforms, you still need warm bodies on the ground. And given how big the front is, you can never have too many boots on the ground.
So Russia's sins here are two-fold.
1st they fight a non-high-tech old-style war
2nd even with old style war they refuse to commit manpower lol
So Russia basically wants to have its cake and eat it too. Sorry, but it doesn't work like that. If Russia wanted low manpower, it should had gone (planned years ago..) with a high-tech military.
Whats happening now is that Russia is getting the worst of both worlds and eventually had to settle down with mass artillery fires which transforms this war to an attritional war and massively slows it down, which paradoxically enough, suits Russia fine because it prolongs the war until Winter when Russia is going to have the biggest leverage against Europe.
All in all, Russia has been proven to be a paper tiger. Can't wait for their 134th marketing/propaganda video on "How these 5 secret Russian superweapons can beat America". And lets not forget Russia getting "1st place" on their Tank Biathlon games lol