I think part of the issue lies with how people create characters. One approach is to take a concept and then shop around to find the best Class that fits that concept. The other way picks the Class first and then tries to shoehorn that Class into a concept. 5e doesn't work very well for the second style.
Those both sound like starting with a concept. Wouldn't "the other way" be to start with a class (or 'build') and come up with a concept to fit?
Sorcerer and Wizard should be equal. They should be mechanically and thematically different, but of a similar power.
And they're not.
Well, sure, in theory, every class should be balanced like that.
And, sure, they're not.
5e has returned to the feel of the classic game, afterall. ;P
If a wizard makes a better magical thief, what's the problem? Why does a sorc class necessarily have to be able to handle all concepts?
Part of it could be a specialist vs generalist issue. The Sorcerer picks spells known and doesn't much change them, so what it can do is much more defined and less flexible than a prepped caster. That greater flexibility is supposedly 'paid for' by the generalist, somehow. That a wizard designed as a 'magical thief' could pick up an enemy's spellbook full of fire spells, and be burninate'n with the best of 'em the next day mitigates against it being a better 'magical thief' than the locked-in-spells-known Sorcerer (or Bard, who, like the AT, would also probably make a better 'magical thief' than either a Sorcerer or Wizard, so I'm really left wondering why that particular example...).
So then Bard is Druid is Warlock? I mean, they're all Spellcasters, they all use components, right?
Prettymuch, yeah. Well, Cleric is Druid is Wizard, 'cause they're all prepped neo-Vancian, while Bard & Sorcerer are hampered by fixed spells known, and Warlocks are short-rest-recharge.
Originally doesn't matter, past edition bias is irrelevant.
5e is all about back-to-basics, core of D&D, past-edition-feel. Heck, it's the
raison d'être. The original Sorcerer is terribly relevant. It's just that its schtick was handed out to every other caster in the game for free.
A class that you have to fill out all the details of can't be an interesting class: there's nothing there to be interesting.
You can do
more with such a class than one with more baked-in fluff and locked in non-choices. Sure, it won't be interesting in the sense of convoluted/detailed/baroque & requiring time/effort to understand & master or give you a ready-made character concept to explore, you have to provide the creativity.
It does matter, the sorcerer class is the only thing that keeps me from returning to 2e and not looking back.
Is 5e really different enough from 2e to make that worthwhile? I can get running back to 3.5 for the Sorcerer (even though it was Tier 2 - you might find a game without any Wizards or CoDzillas to overshadow you), or 4e for the Warlord.
But 2e? 5e has everything 2e has - except THAC0.
There's so many cool tricks you want to play with sorcerers (Careful Evard's Black Tentacles! Black Dragon Sorc with Melf's Acid Arrow! Heightened Planar Binding! Extended Animate Dead!) and then get stymied because (among other reasons) it turns out they can't know the spell in question. Nobody even really knows why their spell list is as narrow as it is, because WotC doesn't explain their logic.
Part of it is no 'named' spells, right?
Would it break any design considerations if you just gave sorcerers access to the wizard spell list? Who knows?
People who liked to complain about 3e just to complain made much of the sorcerer and wizard sharing essentially the same list (but for a couple of spells that affected preparation, which the sorcerer didn't do). They're distinct magic systems made them different enough, though.
That's not the case in 5e, so I guess they felt the need to use lists to differentiate them. Thing is, the Sorcerer list has no unique spells, at all...
But it's not what defines the class.
You don't play the class, you play the individual character.