They need to tidy up the "delay" thing anyway - there was one at the very end of Chelsea vs Man Utd yesterday where Ronaldo was a good yard offside, the lino let it go as per instruction, Ronaldo doesn't shoot and it goes out for a corner which should never have existed. Can open, worms everywhere if United score a winner off that with seconds to go.
As well as the potential for players getting injured in situations that shouldn't even occur (wasn't van Dijk last season along those lines?). No problem with them not showing a premature flag where there's reasonable doubt - remember Jota at Bournemouth a couple of years ago, VAR was in operation and we still got robbed of a valid goal due to crappy officials - but it was obvious in that instance yesterday that it wasn't even close, and even so, they should have the common sense to say "no, you can't have a corner off that".