[greyface-]

> sustain current miner revenue

Why should this be the goal?

I'm sure miners would love to see their revenue never decrease, but this isn't a problem for users or for the security of the network. Block reward does not need to remain at or above current levels forever; it just needs to remain predictable from block to block. Difficulty adjustment works both up and down, even if we've only seen it go up so far. The 51% risk is overblown - the network is significantly overprotected right now, and we could stand to lose a few orders of magnitude without jeopardizing security/availability. Plus, it might even placate the energy consumption doomsayers.

As GP notes, empty blocks are now common, which is in fact a bigger risk in a low-subsidy environment. Maybe we should instead reduce minrelaytxfee to 0.1 sat/vB to incentivize full blocks.