I'm not totally sure, nostr is a protocol and so every new feature has to go through a public process where people can review it, criticize it and help to improve it.

If something will compete or conflict with other existing features, then it will be caught before clients and relays begin to include those features.

Relays don't need to implement all features and clients don't need to support all features. The protocol ensures that relays and clients who follow it will always know what is supported when they communicate so that things run as smoothly as possible.

Users will pick the clients that work best for them. When new core features come out, some clients will be fast to adopt them and they will be for the power users who are willing to test new features and deal with the bugs, then more polished clients will start to adopt them ONLY IF IT IS USEFUL... For example, an Instagram-like client like #olas might not ever need to support custom fonts in messages.

It is chaotic. Life is chaotic. Embrace the chaos and we'll build great things together.