That is a good question.
We have to try to understand WHY we are doing park factors. And it's to (try) to put players on the same baseline.
If we look at 2023 (for illustrative purposes), we can see that Yankee Stadium helps HR hitters and hurts players who get non-HR hits:
https://baseballsavant.mlb.com/leaderboard/statcast-park-factors?type=year&year=2023&batSide=&stat=index_wOBA&condition=All&rolling=&sort=12&sortDir=desc
This is also true at Dodger Stadium. Indeed, if you look at Dodger Stadium year by year, you will see that is consistent:
https://baseballsavant.mlb.com/leaderboard/statcast-venue?venueId=22
Now, let's say you have two batters who are equivalent away from Dodger Stadium, one who is a power hitter and one who is a bigtime singles hitter. But overall, they are equivalent.
At Dodger Stadium, the power hitter will likely be more helped than the singles hitter. Or, for illustrative purposes, let's say this is true.
So the question is thusly: do we want to apply a SINGLE park factor, the same park factor, for EVERY hitter? Or do we want to apply an individualized park factor?
Well, it depends what you are trying to answer. In terms of helping the team win, then you want a single park factor. One batter was able to leverage Dodger Stadium and the other one was not. It's not their fault that they had to play 81 games there. But, that's indeed what happened. And to explain what happened, the one who was able to leverage Dodger Stadium will get the wins.
But, if you try to trade for a player, or try to place all the players in a neutral park (or have them play 5 games at each of the 30 parks), then you'd want an individualized park adjustment.
This is actually far more important for pitchers than batters in terms of asking the question, and yet 99% of the time, the question is asked about batters.