To be honest, I don't feel qualified to speak into the current technical limitations of the existing protocol. But the economics of the blockspace seem pretty straightforward to me. Higher demand leads to higher fees. Even with second layers taking some transactions off the main chain, a hyperbitcoinized world has several orders of magnitude more demand, which increases base layer fee rate and pricing out low economic users from self custody. Anthony Towns has a great blog on this conversation as well.

Both pieces from Towns and nostr:npub1ta5sstxzpk7aykejp6cv8eul80m2rjfwvp3rgjw0xgjtp7s3ak5s0c96f7 are referenced in my piece. ✌️