Well as you know I think it has these - background abilities. But judging from this thread, GM's apparently ignore or override them on a regular basis! In which case, what would be gained by adding more of them?
So how do you rule background abilities in your 5e game? In my experience when background abilities have come up (rarely), the DM has no problem interpreting them in a player friendly fashion. But then, as a player, I’m also looking for the ability to make sense within the established fictional context?
RPGing is a creative pastime. The individuals, plus the way they come together as a group, should make a difference in my view. My personal dislike of "Mother may I" GMing isn't the fact that it affects the play experience, but that it makes for a poor one.
I mean, to look at your jumping example, what's the deep cause of the problem? The fact that D&D measures distances in such a granular fashion! - and therefore requires the GM to be able to form opinions about how hard or easy it is to jump, throw things, hear things, etc at those various specific distances. The issue wouldn't even come up in Prince Valiant, because I'd just say "It's a pretty hard jump - obstacle 3" and then the player would roll Brawn + Agility applying any appropriate penalties for their PC's armour.
So when you set an ad hoc dc in 5e, how is it different from you setting an challenge rating in Prince Valiant. I haven’t played the latter, so I won’t hazard a guess on how obstacle ratings are decided upon, but IME dcs in 5e are not set via the DM consulting charts or calculating numbers, even if those exist, and they exist to a much lesser degree than previous editions. Rather, it’s a similar easy-medium-hard assignation. Further, the swinginess of the d20 means that the player either knows it is likely a failure or success right away. In your experience of 5e (playing or running), what are the stumblings blocks that you’ve seen in setting difficulty ratings?