I do agree it would probably be a bit of an improvement, I'd just question how much. Any result-changing goal in the last ten minutes or so would be bound to get reviewed on the off-chance. And you'd get managers slated if they didn't review, then replays showed someone's nose was offside so they should have done.
I don't like VAR in football because I think there are just too many variables to make it work. In cricket, the stumps don't move, so it's easy to draw lines for an LBW decision because they're in the same place every time. For offsides in football, the last defender will be moving around all the time, different parts of his body will represent the line at any given point, there are potentially multiple different times during a goal scoring move when the line will need to be checked, and different defenders will represent the line at different times. If a foolproof AI system can be developed that can handle all that and check it all in seconds then fine, but the current system of humans drawing lines on a video screen I think will always be inadequate no matter who gets fired or what procedures get changed - still too many variables to avoid mistakes.