I've explained it at length, over and over again: An approach is required to determine if the character can actually jump an unusually long distance. "An Athletics check" is not an approach. It is a mechanic to resolve a declared approach to a goal that has an uncertain outcome and a meaningful consequence of failure. I am in no way against a character trying to jump an unusually long distance. The question is "How?"
The gray area, as I pointed out to [MENTION=6801558]robus[/MENTION], is that the efficacy of the player's answer to "How?" is going to be judged differently by different DMs. He's okay with "I try harder..." (or words to that effect). I am not. Neither of us are wrong.
And to bring this discussion back to the original question, this is exactly why having a formula for determining distance jumped based on the results of an Athletics check doesn’t work with 5e’s resolution system.