Con saves are important on spellcasters because they determine concentration. Sorcerers are the only spellcasting class with Con saves so they should definitely be mentioned. The ability to succeed on your concentration where another spellcaster may have failed is pretty important.
The ability not to be mind controlled and taken out of the fight when the other caster might have been is also important. But we never talk about the classes that get wisdom saves until someone brings it up as a counter to the discussion always focusing on Sorcerer Con saves.
How many times has someone said that you should play a Wizard, Cleric or Druid because they have good Wisdom saves?
Compare that to how many times people say that one of the most powerful features of the Sorcerer is their Constitution saves, something completely passive, that they can't choose to utilize, and in the best situations, they never use in the first place.
Its all about efficacy and tactics.
Metamagics were never about having a spell be not that spell. What it does is open the possibilities of the spell.
Fireball is probably the worse example. It's just condensed damage. The only metamagic you can use that isn't a pure damage boost is distant, careful, and subtle. But their use with fireball in particular is very niche.
Take invisibility. 1 hour of being invisible for a 2nd-level slot.
Well, if you twin it, you've effectively upcasted it. If you need to be invisible for more than an hour, you can extend it and save yourself a whole 'nother spell slot and not outting yourself with verbal casting with only 1 sorcery point. You can quicken it in combat and instantly hide.
Metamagic is not added to make it feel like your spells known list has increased or changed by giving your sorcerer effectively "new spells." Metamagic is used to enhance your spells to push them further beyond what a wizard could do.
And how many times do you need to be invisible for more than an hour, and you know that when you cast the spell? What good is casting it in combat and hiding? Especially on a class that likely does not have the greatest stealth.
And you know, I think you might be able to give me a specific example that fits both of those. "Well what about when...", but think about this... how often do those things happen? Does it happen so often that the wizard needs a second hour of invisibility (and not three, four or more) that is becomes a common problem with the spell?
Not in my experience. In my experience, that is a niche problem. So, you have niche answers to niche problems. And that is your defining design choice, having niche answers to niche problems... which would make your design supposed to be the most versatile.
Except the sorcerer can't be versatile, if they are the one who has the answer to the niche problem, then they are stepping on the wizard's toes.
And this is the constant refrain I see in these debates.
"But you can twin Polymorph and get two Giant Apes, wizards can only get one"
"But you can twin Haste and get two allies hasted, wizards can only get one."
"But you can careful spell hypnotic pattern and set it on top of your allies without hurthing them, and wizards have to place it in a way that doesn't include their allies"
And when you go to look at the Wizard discussions, what do you see?
"With polymorph you can turn an injured fighter into a giant ape. Best healing spell in the game and you can devastate encounters"
"Put haste on the Fighter or Barbarian, and watch them go to town. It is a great way to devastate encounters."
"Hypnotic Pattern can control an entire enemy. Instant win if they all fail their saves, and still turns the tide completely in your favor."
So, no one is saying that they need these spells to be doubled or to be cast more recklessly. These are top tier spells already that alter the flow of combat. I can attest as a Warlock who has used Haste and Hypnotic Pattern extensively. I've never once felt like I wished I was a sorcerer so I could use metamagic on those spells. And we had a bard using Polymorph constantly, and again, no one was watching that going "man, if only we had a sorcerer to make this better" we were going "Oh yeah, we are going to win this fight now. This changes everything."
So, the sorcerer gets a passive benefit that people only talk about because they get little else worth talking about, and the ability to maybe try and eke out niche benefits or get diminishing returns on the great spells other classes are using.