Why?  Big platforms benefit from scalability and economies of scale.  So in the end, while taking a portion, the content creator gets more.

A small piece of a big pie, is still bigger than a big piece of a tiny pie.

And due to scalability issues nostr cant scale to even 1% of bluesky without having to nuke all its data, let alone, compete with a big platform, which themselves are 100x bigger than bluesky.

It's a catch22 situation, and content creators cant be expected to take a large loss, on something that doesnt scale.  This is the market alraedy voting.