Recipients also mine blocks to combat double spends, and everyone will keep their miner running since they may need it at any time and it's free sats anyway.

Semisol

If it’s cheaper to mine, then it’s cheaper to attack the network as well so I’m not sure that matters. More money spent equals more security. If you have to mine your own blocks to get your transaction through then double spending transactions would be trivial. 

GengarGod007

bitcoin

Discussion: Fee market FUD & facts

First, there probably will be pressure to reduce the minimum relay fee. If all users use 0.1 sat/vbyte then the miners can either mine empty blocks with reward or include 0.1 sat/vbyte txs.
Second, it most likely will be cheaper to mine in the future.
Third, there is a high possibility people mine blocks just because they want their own TXs confirmed. LN channels, on chain transactions, lot more.