Isn't that true for a lot of classes with one save or another? Rangers and Monks attribute needs sit perfectly on top of the 3 common saves (hamstrung only in that they get proficiency in Dex, arguably the least important of the 3). Paladins get to add their Charisma to everything (halfway through many campaigns). I guess Dex-based clerics as well. Otherwise, everyone is going to have a weakness in something that is also a tertiary/quaternary priority among their stats.
How does constitution make the sorcerer a better controller? Just the concentration mechanic?
I guess the question is then what is enough. Proficiency and a 12 stat puts you at parity with your own starting save DCs (assuming a 16-17 casting stat), given that the save DCs start at 8 and your average D20 roll is 10.5. Also when the wisdom-based shutdown effects come online and you have the least number of other responses. As you rise in level, your opponents casting stat will rise, but hopefully you will start getting cloaks of protection or ways of getting advantage on saves or immune to effects or the party as a whole has greater responses. Either way, it's not like you can choose to just not be subject to the attack (although careful planning and trying hard not to be is actually a pretty good strategy for both wizards and doubly so the sorcerers).
As for intelligence saves, they are rare, but they can be crippling (Illithid Mind blast effects and such). Of the three low-frequency saves, I think Int is a little rarer but more crippling, and Cha a bit more common but not quite so (Banishment sucks, but at least takes up the concentration of the banisher, unlike a mind blast). It's really Strength saves that lost out in since 2014, with a lot of attacks which procced them now being automatic.
