Or maybe you just don't accept the solution which is "think about how hard you think it should be and assign a DC as appropriate".
There was a podcast a while back talking about a related issue (stealth)
I am not sure stealth is a good comparison since it is opposed. Opposed rolls are easy.
Generally speaking, I think it is more useful to have a list of "common difficulties" for tasks adventurers are likely to engage in, which the knowledge that circumstances are going to impact that thing. In the example of jumping, we know that the basic rule is that you can jump as many feet as your strength score. We also know that a Strength (Athletics) check allows you to jump farther than that. The question becomes what the difficulty for that Athletics check is, and there are a couple schools of thought. The first is that the difficulty is story dependent: that is, how difficult it is revolves around how iumportant, dramatic or fun the jump is. Another school of thought is that it is arbitrary, based on features or circumstances determined on the spot. Another school of thought is that it is standardized: jumping X far requires a DC Y check.
If it isn't obvious, I lean toward the latter case. I don't think story should have any bearing on the difficulty ("story" is a thing that emerges out of play, IMO). I certainly believe that circumstances and features of the environment and situation should impact the probability, but through modifies and especially advantage/disadvantage. Now, here's the thing: I can decide the relationship between the Athletics check and the distance jumped (and there are many different ways you can go on that, all valid) but I would have preferred there to be benchmarks for it in the rules. Why? Because ostensibly the system is well designed with lots of interconnected, moving parts, and knowing what the designers of that system considered "difficult" is valuable to me when I am making rulings.
A lot of people say "rules not rulings" but that is a false dichotomy. It is not an either/or situation. You need rules to make rulings, and rulings make rules better.