I only understand how crypto currency works at a very high level, but from what I can reason with my limited understanding it seems that the ability of a crypto

I only understand how crypto currency works at a very high level, but from what I can reason with my limited understanding it seems that the ability of a cryptocurrency to limit circulation is rendered useless by the ability to create alternative currencies. It seems to me then, that the only differentiation between currencies is marketing/popularity, does it then follow that there's infinite inflation, or would that not matter?