I don't discount the fact I'm likely missing something. But

As a staker: are you sure I should even bother adding transactions to my block? I mean, the additional money I make for staking a transaction is .. 1% of it's txfees? Hardly seems worth the additional orphan risk? (I guess this can be mitigated by in a block race, by policy you randomly select a block, regardless if it was first seen or not?)


As a sender: If a user is willing to pay a fixed amount for a transaction to be included in a block, it means that if as staker can make 100x as much by accepting a direct payment? So if it ever becomes worth the trouble, the entire fee market is going to move off-chain; probably to centralized services? Already in bitcoin we see some very large mining pools offering prioritization services (which small mining pools can't meaningfuly offer), this seems to have the potential to be 100x worse.

e.g. I can envision a service where you have an account and post a transaction (without tx fees) to it. If they stake the transaction for you, they charge you 50% as much as it would've had to pay on the open network. It would make the staker with the service more money, and would save the sender money, all at the cost of on-network stakers.