@goodguy5 there's three problems I see with it, from a mechanics standpoint
1) Keep It Simple, Stupid
2) Other races do a static standing jump in 5e
3) PCs would be more inclined to pick physical / mundane classes for their bullywugs, since other classes likely wouldn't spec into STR, and a racial that did buffed STR scaling instead of a flat minimum to jump distance, would be less powerful for caster types.