there has literally been hundreds of proposals. over many years but they never get passed the cabin of core dev moderators that only want to follow their own roadmap, and not actually be open to diverse community consensus.
open source development is merit-based. it's not a charity or a lottery---no one cares if "hundreds of proposals" exist if they're not worthy of coding, testing and merging. core is like any other FOSS project. if a proposal can't reach rough consensus among core developers, why the hell would core implement it?
you should go code your own implementation or submit proposals for an alternative implementation like btcd, knots, bcoin, libbitcoin, bitcore, etc. what you're talking about is a big part of the reason alternative implementations exist at all.
the truth is, your feelings aren't shared by the market. since bitcoin is an opt-in, voluntary network, it's up to the actual users to reject core and pursue an alternative. if bitcoin users were opposed to core's development process, they'd run alternative/incompatible versions. a few actually do that, but the vast majority of node operators don't. your issue is with
them, not core developers.