A team isn't drafting Richardson for what he did at UF. They're drafting him because he's only 20 years old, is one of the most physically gifted QBs ever (6'4" 240 with 4.4 speed and a howitzer for an arm), has good character, and could become a generational QB if he pans out. Basically, they're thinking they could get a Josh Allen type talent.
Is that possible? Sure. It's also possible that Richardson is a total bust. He has a lot of developing to do. But I'm not so sure it's a bad idea to take a kid who could be a NFL MVP or could put you in position to be picking a top QB prospect again in a couple years. It's arguably better than having a QB who is just good enough to stick around but not good enough to get your team over the hump.