This is true. Eventually only the coins with a genuine use-case will survive. Those that don't will slowly fade to nothing, but we are a long way from that point. I would imagine we have years of volatility and speculation-driven prices ahead of us. The bad coins will disappear, yes, but for now and the medium-term future they will remain.

As for the coins you mentioned, I like ADA. This coin does have a real use case and a great development record. It is perhaps too early to judge them, but the potential is certainly there.