I sure don't care about spending 0.1% or 1% per year of my wealth to keep Bitcoin secure.
You are free to send coins to addresses like bc1qqph8gusf2x7ch4xjs8vnp7hy449r929wnv5jggmy678gam85l6rqgajus9. It has "1000000 OP_CHECKLOCKTIMEVERIFY OP_DROP OP_TRUE" script, so it can be claimed after a block 1000000 by any miner.
But I do care that everyone else also chips in so we don't have a tragedy of the commons.
So make it a soft-fork proposal, where N out of M coins are locked in every coinbase transaction, to cover future rewards. It will have higher chances of being deployed than any other hard-fork, and will also increase future mining rewards. You want to get a 0.01 BTC tail emission? No problem, just send 0.01 BTC to block 1000000, then 0.01 BTC to block 1000001, and so on.
So where are the examples?
What about RSK? Of course it is not an altcoin, but it works only on transaction fees.