Assuming that a gap year or more as a safety plan is a conscious decision, not an April panic after a shutout.
Also, the gap year student needs to then make a new less selective list for the next try. But then couldn’t those colleges be on the first application list?
An EA or rolling admissions admit was to me a safety. For my son, that meant the flagship, which would also be free.
Since son applied as a junior, almost everything else was a reach. We agreed we’d only visit the schools he was accepted to .
Receiving admission and sufficient FA/scholarships to make the college affordable turns it into a safety at that point, even if it was a reach at the time of application.
Ahh, but “accepted and affordable” is a different position than selecting where to apply that includes a reasonable backup plan.