> But who will control the miners at L1? Fred again. Fred can charge higher fees for his L2 sequencing and inclusion services, and increase his profits, if he controls both paths for getting transactions on-chain.
I don’t see why this is true! Recall that the existence of MEVAs means that individual miners have much less ability to affect transaction sequencing, and so Fred now has much less economically exploitable advantage over other miners than he did before. So it’s much less likely Fred will try to also dominate the mining market.
> With MEVA, by contrast, ordering rights are auctioned off for multi-block periods
Agree that this is an important difference! Though you could easily imagine a system that has a block-by-block MEVA, or even something fancier that allows immediate buyouts of sequencer power, like a Harberger tax.
Also, note that MEVAs open the door to alternative mechanisms for replacing bad sequencers (eg. some form of DAO) which could greatly reduce exploitability in practice.