You still don't seem to understand what goes into a VAR decision or how VAR actually looks at anything.
Because the area of potential VAR interventions is limited to straight red card offenses, goals, and pens, it's far easier for VAR to dismiss the vast majority of what happens in the game. It's easy to see that 99% of challenges are not straight reds from a quick glance. And it's almost universal that when an orange challenge happens play naturally stops anyway. The team that got fouled usually doesn't try to quickly restart play after their teammate nearly gets stretchered. So VAR naturally has time to review angles and determine if a clear and obvious error as occurred such as a missed red. The same for potential fouls in the box or near the edge of the box and obviously the same for goals.
It takes time for VAR to review the angles and determine if a clear and obvious error occurred. Most often thus occurs either during live play (i.e., the ref waved away a foul in the box and the ball stayed in play) or at times when the game is naturally stopped so the interruption is smaller, but it still happens.
If you expand that review to include yellows and potential yellows you now add a *massive* number of events that need to be checked in further detail which dramatically increases the chances that VAR would disrupt the game. Every single time players come together/there's a foul, VAR now doesn't need to just look for a second to see if it was a straight red, but has to look to see if it was a potential yellow card. Every time the referee plays advantage, VAR now needs to spend time reviewing angles to determine if it would be a clear and obvious error to either award or skip awarding a yellow. If a player is starting a bit of a break and is brought down, but his team wants to restart play quickly, wait they now can't do that because VAR has to finish it's check first to determine if the professional foul was worthy of a yellow even though the ref was happy not to award one.
