My concern about increasing ability scores potentially being a sign of or cause for broken math in the system seems to have an answer. Straight from the WotC Q&A:
If a character takes "add +1 to an ability score" at every feat slot,
will that character "break" bounded accuracy?
No, for the simple reason that we have ability score maximums in place. Since
you cannot improve an ability score above 20 without some magical means, we
aren’t concerned about players reaching high primary ability scores, because the
highest they can go is still capped.