TwoSix
Everyone's literal second-favorite poster
I'm not disagreeing with you, but I do think some of this is DM specific. (While also acknowledging that I've absolutely seen DMs who run the way you've described.)I can’t stand the arcana, history, religion triad for the simple reason that most DMs I’ve seen make any kind of knowledge check one where having any one of those three is acceptable for attempting the check, therefore watering down their value. Better to simply have Knowledge as a check then.
I’d argue that most of the time Acrobatics is in the same boat as the Knowledge triad. It’s allowed to be substituted for Athletics almost all the time.
In my games, Arcana covers magical processes and creation, Religion covers pretty much anything extraplanar or otherwordly, and History covers everything to do with current or past material world civilizations. There isn't a ton of overlap, and I often don't allow checks unless the character is proficient.
Likewise with Acrobatics; most DMs in my groups are very firm that Acrobatics can NOT be used for climbing, jumping more than a small amount of height, or swimming.