Hot Take: Feats should not directly modify damage
IMHO feats that directly modify damage output are the worst kinds of feats. They are generally quite boring, yet at the same time practically mandatory from a gameplay perspective. A player who takes multiple such feats is often many times more competent in battle than one who does not, essentially turning such feats into a "tax" on character building.
I would much rather have classes themselves provide all the necessary damage capabilities to meet whatever baseline the designers are targeting. If a class needs a damage boost, don't make the player take a certain feat (or combination of feats) to meet their projected output.
Instead, feats should provide new capabilities and options for players that do not directly affect damage output. For example, GWM could allow Heavy weapon wielders to make powerful strikes that push foes back or knock enemies prone. Sharpshooter could allow a warrior to make called shots that inflict conditions to hinder their foes.
I want to see feats that add more utility and options, both on and off the battlefield, instead of these +X damage 1/turn or complete negation of downsides that that so many 1D&D feats have fallen into.