As you advance in level, you gain a number benefits that improve your capabilities. These benefits are called feats. Typically, a feat doesn't give you a new ability, but instead improves something you're already able to do.I stopped playing AD&D 2nd Edition when I was in high school. My reasoning, at the time, was that you couldn't find enough variety and mechanical (game rules) support to differentiate one fighter from another. In retrospect I don't think I was 100% correct about the game itself but there is at least a speck of truth to the concept. Third edition's feat blew this complaint away. No longer were there very few and limited levers to customize your character. Fourth edition took a step back and feats no longer strongly distinguished one character from another.
I'm biased against feats that impact numbers without representing any difference between characters. No one looks across the table at my use of weapon focus, to do 1d8+5 damage instead of 1d8+4, and says, "wow, we're did your character learn to do that". One, the bonus is relatively small and thus unnoticeable. Two, it carries very little connection to how you're a different flavor of warrior. Three, it gets hidden in the numbers; you don't typically tell anyone your mathematical bonuses while playing in-character. Four, it looks the same as what every character does. Worse than relatively optional feats like weapon focus was the introduction of weapon expertise (and versatile expertise). Hitting is fun. Missing is not fun. Because 4e is so dependent on tactical effects that usually come from hitting your target, the expertise feats were almost mandatory.
You really don't get very many feats between 1st and 8th level. Thus, taking an expertise feat just to be competent against the enemy was the right decision but it was also boring as hell; sort of like paying your taxes. Basically everyone took it or knew they "should" have taken it. I think characters need more feats, one every level, instead of fewer so I am completely opposed to effectively levying a tax of -1 feat on all characters. If game math requires everyone to hit +1 better then just give it to all characters or conversely give -1 defenses to all villains/monsters/enemies.
Feats were less interesting, less flavorful, and less fun in 4th edition. I believe the game designers were chasing a reasonable goal when they (unintentionally) took away the essence of feats. Some feats were a huge problem. Adding rules, through feats, added complexity to game play and created hard to manage rules interactions. Some 3e feats were positively broken. The spiked chain, improved trip specialist could pin an enemy down who couldn't stand up without getting tripped again as a "free" opportunity attack which triggered additional damaging follow-up attacks from the spiked chain.
A few feats had great potential but missed the mark. There weren't really enough energy spells of certain types to play non-fire Elementalists. Some feats exist to differentiate but also act as a gate to "let me play the character I want to play". Third edition's weapon finesse feat let you play a stereotypical variation on the fighter based around dexterity; this was especially useful for halflings. You spent the feat for the "right" to play a halfling fighter which is, not unlike certain 4th edition feats, akin to paying your taxes only this tax only applies to people who aren't adhering close enough to the social engineering in the game. Jump back to elementalism, energy substitution came to the rescue but with a slew of extra taxes: first you had to have spent 5 ranks in the knowledge (arcana) skill, you had to pay a feat to get "any other metamagic feat" as a prerequisite, and you had to spend a feat for energy substitution itself. Sorcerers got to pay a bonus tax: any spell a sorcerer modified with a metamagic feat got increased in casting time to be a full round action. I don't recall any attempts by the sorcerer character class to overshadow the game so I never understood how metamagic feats would break this class without its own little metamagic tax. At this point players should just politely ask the DM, "is it okay if I invent my own spell called Melf's Delayed Blast Acidball" and be done with these game designers.
A feat should carry more of a benefit than just letting you play the basic game. Everyone can hit things and it isn't really important if you use strength or dexterity. The feat you pay for the privilege of using reasonable alternate stats should also come with a benefit. Preferably a benefit that makes a dexterity fighter feel and look different than a strength fighter.
Bring back variety. Bring back flavorful feats. Let our feats heavily define us (not completely but enough to be quite noticeable).