That's a False Dichotomy. You don't need to be able to do every single thing athletic just as good as every other thing or else have every possible athletic skill be individualized.
There were no holes in 3e physical skills. You had climbing, which left no holes in climbing ability. You had swimming, which left no holes in swimming ability. And you had jumping, which left no holes in jumping ability. There was no general athletics skill that applied to some and not other skills and would therefore have holes in it.
If you prefer to have gaping character flaws in a PC that is supposed to be good at one aspect(climbing), but not another aspect(swimming), yet is great at both, then the 5e skill system is for you. Or maybe you just avoid making characters that aren't good at everything in broad categories, which itself is a character flaw. People aren't good at everything in a related skill.
I was an amazingly fast sprinter and at one point was training for the Olympics. I was also a fairly good climber. Thing is, I sucked at long distance running and jumping, and was an average at best swimmer.