This is part of the crypto-evolution. We need to remember that the whole market is still very young and immature, there is a huge evolution yet to be made.
Eeryday new Altcoins are born and some others die out, and new coins bring some new features or use cases, and older cons also evolve and update... it is a dynamic ecosystem...
Bear markets bring balance to the crypto scene and exterminate a lot of useless alts...
Take privacy coins for example, the older privacy coins like Zcash or Monero are adapting and updating, while a new generation of evolved contenders have arrived to solve a few problems that still exist, like Veil project or Beam... only time will tell which reaches a greater adoption level