This would be less controversial but for (a) the Wirtz goal allowed that looked well offside and (b) people not understanding about needing two opponents nearer the goal-line.
There's also the problem of defenders pushing attackers into offside positions (or
maybe in this case Haaland being held in an offside position). But the ball was close enough to Haaland that some thought it brushed his backside so if he hadn't been there the defender should have been able to play the ball - but if Haaland wasn't there where would the defender be? And but for a City player in front of the GK could the GK have got the cross anyway...
And a case that both the scorer and another City player were being fouled before the crucial "moment the ball was played".
Anyway (proper fan post), there's some satisfaction that City got their second goal in the time added for the VAR delay!
Knock yourselves out: