Although saves don't scale too favorably at higher levels (off-saves anyway), I don't think there's a balancing issue. Players can choose to boost stats or take the Resilience feat if they feel like a particular save is going to be problematic. Fighters usually do this anyway to avoid issues with WIS saves, and it's a good practice for other classes that want to shore up weak points. The real problem is that players aren't usually interested an ABI or feat that doesn't somehow contribute to their primary function; that's a problem with the player, however, and not the game itself.
Most of the worst save-or-suck type effects are usually spells anyway, and if your Sorc, Warlock, or Wizard thought it was a good idea not to pack a Counterspell then it's on them when an enemy mage ruins everyone's day. Of course, Counterspell isn't as fun as Fireball, so a surprisingly high number of players won't actually take it -- or worse, they'll take it but still choose not to use it.