Applicant numbers are falling so ratios are probably better than a few years ago. I don't think there is a problem for strong candidates applying in Yr 13, and others will get stronger simply by having the year out, having A level grades under their belt, and gaining experience and maturity.
It ought to get easier still in a few years if medical schools are expanded as promised.
Taking a gap year is not a bad thing. DD has a summer term birthday, and decided quite late in the day to defer her offer. Yr 13 was tough, and she did not want to go straight into first year medicine without a chance to draw breath. She is having a great time, busy but in a very different way, and gaining a different set of skills. And it is so nice to have her at home without the pressure of school, exams and UCAS.
Its much easier if you can see it as a two year process, with the first year as a practice round, getting a place as a bonus, and the priority being getting the best grades possible. Though, obviously, easier said than done.