It's just hard to compete with the network effects of established players like Twitter.
The product needs to be easily 5 or 10x better in the eyes of a normie and I dunno how this could ever be that. Maybe if this whole thing can also just import X posts into it or something that might bootstrap things.
Or perhaps just the various other services and products that use nostr also gaining traction might help...
But yeah I dunno, atm it is just too niche and it will remain niche imo due to the barriers and challenge of network effects.