there is embellishment/exaggeration and outright lying; college applicants do both (in ECs, essays, awards, AP scores); prob a bit harder for BS applications but not impossible. Its hard to claim to do so many amazing things by age 13/14. BS applications also allow you to upload links and media (for ‘proof’) so maybe they look into those as well.
Do some of these applicants get in? definitely but they prob had amazing grades and stellar recommendations as well
No BS or college has time to do background checks on applicants or matriculants