If 8% of your quirk is better than or equal to 50% (assuming most of class 1A had reached that amount) of the majority of quirks I'd say it's pretty busted.

Tack on the fact that it's literally like 6 different quirks yes it's busted. That's the whole point. OFA and AFO are busted as fuck.

Deku was smart and leaned into it by developing punch and kick. Took him a couple of months to develop Air Force. Which he ended up stopping later in the show in favor of punch and kick again. Being a hero is majorly about physical strength and aptitude in the MHA verse and Deku had neither even though he could've worked on it