What you say can be true especially coins that come from mining, except centralized coins created by banks such as Ripple for example.
If we pay close attention, every new coin that appears, always seems to drop the coins of its predecessor, with the pretext that the innovation it carries can work better than its predecessor. For example, coin A will kill coin B, coin B will kill coin C and so on like that, indeed this thing can be said to be reasonable, because their nature is decentralized meaning that all conditions will return to their users, because only they who can determine the good and bad performance of cryptocurrency. I think it's time for us to abandon such assumptions, now we have to think more mature and don't let the coins we're proud of continue to decline in price.