Old, but:
Why would someone want to play DnD, PF, or a d20 variant and not be powerful?
Because several of the D&D systems
aren't made specifically to be a powerful person. AD&D 2E's focus - as one example - was more about fantastical medieval (and, if far less successfully / with a lot of erroneous pop culture presumptions, Ancient / Hellenistic / Renaissance) adventures and role-play with combat often
secondary or
tertiary to everything else. There's a reason - if you look through a lot of 2E's adventure boxes that're meant to be anything more than compilations of one-off murder hobo distractions - the vast majority of chapters and side-adventures focus on stuff like the PC's playing humble or waiting to ambush a force when it's under-strength or getting a force multiplier from allies or something. Heck, there's a reason that at higher levels of 2E one of the most common upgrades for classes (with only Wizards and a handful of other classes the exception) was
getting a rump-ton of minions to lead around, whether through example or charisma or seniority or whatnot.
Don't get me wrong, 2E could very much get broken (Polymorph, Other is
only acceptable as a 4th Level Spell because of aforementioned 2E spell progression and the fact that the DM can withhold it as long as necessary: I'm not kidding when I say that otherwise it would allow a Level 7 2E Wizard - solo - to kick many Level 13+ 3.5 Parties in the shins and take their lunch money), but a lot of the game was built around a presumption that your character would have at
best maybe one or two stats above a 12 (and statistically one or two hovering around 8 or less). Unless the DM fiat'd otherwise, there was a level cap that for several PHB PC races capped out around Levels 12 or 13 (sometimes even lower). Statistically the average Level 20 Fighter would have only ~82 health before Con Bonus (which statistically would likely be +0 unless one of said lucky rolls) while the Party Wizard would be lucky to clear 35 at the same point. A character with more than 15 in their primary class attribute was considered so lucky and fortunate and blessed that they got an additional 10% to all experience gains for the respective class because they were assumed to just have
that much an advantage over their peers. And this was a system where attributes - barring rare / DM-delivered artifacts - were
static: What you rolled on your 3d6 down-the-line was what you'd have from Level 1 newbie to Level 20 Epic Adventurer.
This is just looking at 2E, but the point being D&D is not attached at the hip to optimization. That didn't start until... some point in 3.5, and even then the game did not
begin that way so much as get lead towards it by an increasing expectation of system mastery by the players (in the era of 2E it was not unusual for literally
nobody but the DM to have
any books: PC's were often rolled on the spot at campaign's start or even pre-constructed by the DM and players allowed to pick from a list of sheets. 3rd edition changed that, and at some point in the day of 3.5 this mutated to a point that three prior editions worth of presumptions about character sheets held less often than it did).
