I think the ideal in designing balance between character builds is that every possible build is on par with every other possible build. Your build choices should decide what and/or how you want to play, but not your power level.
For logistical reasons, this is impossible unless you make the differences between options so small as to not matter (eww) or the number of choices very, very small (also eww).
Still, balanced games are usually more fun, so, if you can do something to improve the balance of a game, without removing fun, you definitely should. That caveat is important: Balance isn't everything. Fun is the important factor that balance just contributes to, and there are plenty of very fun games that are also woefully unbalanced. If you remove fun or interesting things in the name of balancing out the different character choices, you've probably achieved a net loss.
I think you could definitely remove ability scores without losing fun. I mean, is messing around with your stats, moving one point to another, fun or interesting? I don't think so: The fun and interesting parts of characters in D&D comes from discrete abilities that character can actually do (spellcasting, trapsense, rage), not from the scores that provide mechanical bonuses to these abilities.