I do not know whether or not VAR is affecting the ability or willingness for onfield officials to make decisions, only they could tell you that, however, their answer should be that it makes no difference.
I can tell you that De Bruyne was cautioned for the offence leading up to the penalty, although that took some time if memory serves me correctly, possibly because of it showing the VAR reviews.
Next season De Bruyne would escape the YC (assuming it was for preventing a promising attack) because advantage was played.
Another rule that doesn’t need tampering with!
The VAR should be used for a clear mistake. Everyone can make them, have a bad position etc.
A good example is the Man City v Man United. Rashford clearly fouled in the box Taylor unsighted and VAR intervenes to give the correct decision.
I haven’t seen much evidence of this so far!