I still say the game would be a better TTRPG with only four ability scores:
Brawn
Agility
Intellect
Personality
You have to change the names or else people will associate them with the older categories.
The only major issue is that it's not always easy to give monsters lots of hit points. But, if you want to have monsters that are really beefy but don't have high Brawn, just give them more hit points. You can do that. You can just cross out 10d8-10 and put in 10d8+20 if you want them to have 65 hp instead of 35 hp. The game totally lets you do that.
If you really, really want to make it all codified, you can just make abilities that change the stat used to determine hit points away from Brawn and instead use something else. This Air Elemental uses Agility instead of Brawn. That Lich uses Intellect instead of Brawn. That Beholder uses Personality instead of Brawn. Hit points represent your ability to ignore or avoid damage, so just lean into that and make hit points for some creatures based off what makes the most sense for that creature.
Unfortunately, you can't really change this aspect of the game anymore. The six stats are central to the game and changing it would make it Not D&D.