If your strategy doesn't include ramping up in mana, drawing a bunch of cards and using the broken tutors to fetch up the mistakes in magic's history, chances are you are going to lose to the decks that do.
Since Magic is a resource game every strategy falls into either increasing your resources , decreasing your oponents resources or using ones resources more effectively. Thats why I want a specific strategy that doesn't fall under that, and that is a strategy that really gets irellevant but not because of card choices but the way the game works.
Every blue deck I make has the same ramp package, the same draw package, the same tutor package.
Then don't and yes you can still be competetive to an extend with weaker cards or different cards (does not neccesarily apply to CEDH).
If these cards weren't so standalone broken
As I said earlier there aren't that many Standalone broken cards most are synergistic broken.
Sure there are some standalone broken cards but even they do not neccesarily fit in every deck. Like the example you gave earlier with enlighted tutor I don't run any in my paper decks (Budgetary reasons), and only in one of my 3 white decks in Modo as thats the only one that really needs it.
And the win records of all those are the same.
Like if my choice is diabolic tutor or another threat, suddenly I have options.
You do have that choice with demonic tutor as well. Sure demonic tutor is generally better because it can get you anything (Nothing beats sad dem tutor for a land :D) but if you are fetching a threat most of the time you can just play a threat instead of the tutor, and your chances of winning dont go down significantly. If you however look for many different types of cards then you are in a playgroup where you need that utility and there you should probably take the diabolic tutor over the threat as well irregardles of the high mana cost.
Yes there are some niche commanders like that (Mostly due to direct and unique abilities as those usually build around that effect making it easier to theme stuff around it but also making lists more similar) but even there people don't play carbon copys either due to budgetary or powerlevel reasons. Go to EDH rec or any other site that shows you the percentage of decks that play any given card and you'll find that in most decks the count of cards with more than 50% inclusion is below 20/60 nonland cards leaving 40+ cards usually varying wven with the same commander. And even with most niche commanders that count rarely goes above 40 still leaving 20+ cards varying. And add to the fact that noone forces you to even play your lists like that just like following the templates. Both EDHrec and Templates are a good starting point especially for newer players but you can adjust those to your style of play, playgroup, budget etc.
And as others have stated with the exception of (maybe)mana rocks most slots of the template you used can be filled//are often filled with synergistic versions of such cards making it less staple more synergistic. Making finding those "the interesting part of the deck[building process]"