For instance, it's surprisingly viable to make a mediocre-INT wizard heavily invested in DEX or CON ("just" avoid spells that force saves or take attack rolls).
Yeah, but again... how is that a problem?
So there's a wizard that has a mediocre INT and has raised their DEX and CON. Okay. Good for them. Why is that a bad thing? Why are characters that have higher DEX and CON stats such an issue for people?
There's only ONE reason why people get all bent out of shape over PCs that have higher DEXes and CONs and lower INTs and STRs...
"Because it's cookie cutter!" "Because every character is the same!" "Because I'm bored of seeing it!"
Well why are you even looking at these character sheets to begin with? Guess what? If you are a DM and are tired of seeing cookie cutter characters, it ain't the numbers on the character sheets that are causing duplication and your boredom... i
t's your PLAYERS who can't seem to roleplay any differently no matter what their characters are.
If you've seen three archery PCs that have maximized their DEX, CON, and taken the Sharpshooter feat... yes, you will see three characters that have good ranged attack bonuses and do good damage. Just like every other character at the table will have a good attack bonus and good damage. But none of those three archery characters will feel the same if the players actually create three distinct personalities, each with their own virtues, flaws and quirks.
The numbers on the sheet are
meaningless unless the player actually roleplays what those numbers mean. Having written down a +4 next to the letters D-E-X on a character sheet is no different than having a +4 next to the letters S-T-R. They are both a random number found next to a random set of letters scribbled down in pencil on a piece of paper. None of that should EVER affect a DM or make them "bored" because those table scratches do nothing whatsoever until the DM or player
roleplays what those letters actually represent at the table.
There's a reason why AD&D existed and was so popular and memorable even though every single Fighter PC had almost the exact same small number of game mechanical abilities and capabilities. Because the numbers on the sheet
aren't the character. So stop looking at all these pieces of paper and saying "Hmm, why do these all look alike? We can't have that!" And instead see what characters your players have come up with and are playing. You'll most likely find they aren't all that similar after all.
(And on the off-chance they are... that just means your players can't roleplay original characters, and no amount of changes to their character sheet is going to change that. The character sheet is just the symptom, not the disease.)