I suspect what you're doing is looking for concepts that fit the rules you can optimize. Or to put it another way, you're looking to make the absolute best version of a given concept, as it relates to the combat mechanics of the game; if faced with two options for similar concept (is Captain America a paladin or fighter?) you'll probably choose the one that's most mechanically advantageous.
Ah yes, the ever not-so-subtle, "You're not really being creative you're just covering up dirty dirty min/maxing!"
Who wouldn't want to build the best version of their concept? Captain America has no magical powers, therefore fighter, better fit for the concept. Also, the only way shield throwing works is either with some kind of house-ruled "Shield of Returning" or with the Eldrich Knight's weapon bond bonus action weapon summoning.
Why would you make a less-than-perfect realization of your character? Inevitably, whether you are power-gaming or role-playing your heart out, that leads to dissatisfaction and a desire to re-do until you get it just right or make something else entirely.
It's like Magic: The Gathering where the best players don't just start by grabbing some random cards and building a tourney deck from scratch. They look at what is currently being played, what's most effective, and has the best chance to win. They go play the tourney and that's great. But take that type of player and pit him against someone who literally just wants to build a theme deck, or a deck that's good but maybe not anywhere close to good enough compared to yours, and you'll have lopsided games almost every time.
As a person who plays MTG and does both I'll tell you that there are some concepts that are inferior to others...but that doesn't mean you don't want to make the absolute best version of the deck where the "best version" is where the deck does what you want in the most effective and efficient manner. I apply the same logic to D&D character building. How can I make the
best Captain America? How can I make the
best Indiana Jones? I don't care if my Indiana Jones is sub-par to Bob's Wizard2/Fighter5/Paladin7; because my character is the best darn Indiana Jones at the table.
You're fundamentally misunderstanding optimization and assuming its only use, and the only intention of such is to "win" over everyone else at the table.
It's the classic hardcore vs casual or professional vs amateur scenario. I'm in no way saying that min/maxing is bad. I understand that some people (I used to be one) are attracted to being able to make any given concept as efficient as possible. Their the ones who will dump the 8 stat into charisma because the fighter doesn't need to be pretty. Other players may choose to dump the 8 stat into wis, knowing full-well that's not a smart choice to make, but they are willing to do it because it makes a more compelling character for them. These two types of players do not work well together for any long period of time, and amazingly it's always the min/maxer who is clueless as to why it's a problem.
Oh boy here we go again another white knight on his high horse about how the kind of mind-maxing that he doesn't like is bad because he doesn't like it. Bob who optimizes for his character to be the best darn *concept* that he can is NO DIFFERENT from Joe who optimizes his character to be the best darn fighter-with-no-personality. They're
both optimizer. They're both trying to win. But what you fail to understand and where the distinction truly lies between bad power-gamers and good power-gamers is what they're trying to win
at.
Bad power-gamers want to win
against the table. They want to be better than everyone else. Good power-gamers want to challenge themselves, to "win" against a bar they set for creating something they enjoy. Be they role-players or number crunchers. That's what makes the difference.