I generally try to maintain the naive attitude that refs do their best and just have an unenviable job, but it does become hard when not a year goes by that there isn't a match-influencing or other football-related corruption scandal going on somewhere in Europe.
My general outlook is that referees favor the bigger clubs subconsciously even if they aren't trying to.
I think the truth is somewhere in between.
PSG getting screwed over vs Barca, Real vs Bayern in Munich, Bayern vs Real in Madrid, Juve vs Bayern last year in Munich, etc.
Those are all big clubs.
In most cases though, the home side somehow gets the most calls.
That said, the general atmosphere in stadiums, fans foaming at the mouth and jeering and booing a call going the other way no matter how obvious - and more importantly, players diving, cheating, whining, faking injuries, crowding the ref, etc.
The football culture is in such a bad place, it's pretty disgusting to watch at times.
Last week Atleti vs Real, every single decision the ref made he had 3-4, or more players in his face, crowding him. No matter how obvious the call was, no matter how benign - both teams did their best to squeeze out any possible advantage they could get with the ref... And basically pressure him into making mistakes for their side.
I said a lot of times, video replays and retroactive bans for diving and faking injuries are a start; but the the whole can only be fully dealt with when crowding a ref, swearing at them, etc... Results in cards and, in case of swearing, etc.... Subsequent bans.
If they want football to return to at least some form of a sport where respect is a thing, something like this has to be done.
...
I do think first year with video refs will be hilarious at times, as I'm sure you'll have a lot of cases when players will be protesting and crowding the ref even AFTER video replays.