Bitcoin Magazine made good article about it,
2020 and Beyond: Bitcoin’s Potential Protocol UpgradesBut there aren't any ETA of when the upgrade/update will be deployed to Bitcoin mainnet, in fact most upgrade/update don't have ETA until the development process (including testing/find bugs) is 100% done or a consensus is archived.
There are few suggestion to lower defauly minimum transaction fee (e.g.
#14012,
#13922 and
#13990) which allowed to be broadcasted by a node, but i doubt it'll happen anytime soon.
Schnorr/Taproot/Tapscript probably is what user wanted since it lower transaction size, which means users will pay less fess and allow more transaction in a block.