You say that but you would still get into he realms of clubs being upset about decisions going against them. It's not as if the Forest incidents weren't reviewed by VAR. Change the structure and introduce challenges and Forest are upset that they believe 3 clear penalties were denied, even with said challenge system.
In tennis (and cricket) at least, the challenge system is not to make subjective calls but stating whether the ball was in or out. Whether a batsman should be out based on clear technology.
The fundamental issue in these incidents is the subjectivity of handballs, penalties, red cards etc. I just don't think a challenge system makes things better.