A blockchain's transaction capacity is equal to the capacity of its L1 plus the capacity of all L2s under its security. https://i.imgur.com/jAyzYVi.jpg

What is the incentive to pay for Eth’s security in perpetuity, assuming the L2 can gather significant assets?

Head of Research @ Blockworks Research. @_RyanRConnor on twitter/X.

Yea, I guess that’s what I’m wondering. It’s it more EV positive to be an L2 or be your own chain and launch token, get MEV, etc

The reason to pay for Eth's security is that you get Eth's security

Meaning: your users have very strong assurances that they can always withdraw to Ethereum

And a small nitpick: an L2 that isn't paying for security from Ethereum (or another secure L1) isn't an L2, it's just another blockchain.