VAR will always be contentious when opinion is involved.
Show 10 experts a penalty decision and 5 will say def pen and the other 5 will say no way.
Even on off sides it not so simple. I saw one on MOTD last week that didn't have var.
Ball slipped through for midfield runner but the flag goes up for offside, back 4 & goalie stop but player puts ball in net. Replays show player is onside!!!!
Whats the decision given when var is studied, defenders can rightly say the flag went up or do we ignore linesman in future, if so what's the point having them.
The current goal line technology is as far as you can go without spoiling the game.
Any other decisions need opinions from somebody and that takes time to formulate.
Leave it as it is.