There’s a long list of runners with Power 5 worthy PRs out of HS from powerhouse HS programs that just decide to hang it up after HS because the fun of the sport was ruined for them.
Of those who seemed to genuinely want to continue the sport and inexplicably couldn’t do the tasks necessary to be a college student and continue their careers, I think of the Long Beach Poly national record 4x8 relay from 2011. I don’t think any of those guys ran in college, including the ~1:47 leg.
Another name that pops into my head is Luke Gavigan of NY, who was 1:52/4:07/9:10 in HS and committed to Penn State but to my knowledge couldn’t ever become academically eligible and for some reason let that stop him from pursuing his athletic goals. I don’t think he ever ran a competitive race again after HS.