it's inevitable that new and better ways of doing things will be discovered
You're referring to altcoins. Of course, new coins will emerge while others will be forgotten. It comes back to endless debates about what's the best between BTC vs XXX
But don't forget Bitcoin can also evolve and remain competitive. There's a lot more to improve, Segwit didn't come the day 1. There are also multiple things like MimbleWimble, Schnorr which will help BTC
But is it really about just being first in today's world?
No, it's about the most robust and the most useful
I like to compare Bitcoin with Debian. Debian is the mother of most GNU/Linux OS today (Unbuntu, Zorin, Lubuntu,...). It creates different OS, for a different population, different needs, different communities, etc but in the end, Debian is still the queen, proof: devs keep to fork it