serious question: why wouldn't Pump.fun or other successful apps on Solana move to their own chain?

collect sequencer fees, better UX, token utility through staking, etc.

What composability do they really need that they couldn't add to their own chain? (dex, defi, wallets)

Feels like too much stress/Work for something that doesn't seem really needed for the memecoin eco

Just be on already established chains and use their momentum to rack up fees.

Plus I'd also question if Pumpfun is successful because of the innovation of the app in itself or the chain on which it's built