When you apply (via ERAS) or try to match (via NRMP), I can't tell if this is the first year you are applying, or if you have applied before. The only way I can tell is by reviewing last year's applicants, which is honestly more work than I'd care to do. So there is no "reapplicant" flag, or stigma.
However, your best chance at matching is the year you graduate. Every year that passes decreases your chances of matching. So, applying and not matching will hurt your application the next year, as would just taking a year off.
Also remember that applying a second year isn't an independent event. If you flip a fair coin and get heads twice in a row, and then you flip it again, the chance of heads is 50%. Each flip is independent of the prior flip. If you apply and don't get a spot, the next year your chances are decreased -- not because you tried and didn't get a spot, but because whatever caused you to not match the first time still exists the second time.