To me the real problem is in the progression.
Rangers have crappy progression: For level 1 they are basically a strictly worse version of the Fighter, albeit with an additional skill. The Favored Enemy and Natural Explorer abilities are likely to not come up through your whole play of level 1. They then have an awesome levels 2-5, which is the saving grace here given that this is where so much of play happens, but the rest of the progression seems interspersed with a lot of semi-dead levels. There's some really cool subclass abilities and some really cool spells but it just isn't enough to keep me excited about each level up.
Do Rangers suck? Not in raw power. They totally carry their weight on the back of spells and subclass abilities. They just don't develop in a satisfying way or have core class features which I find compelling.
Sorcerer's have terrible progression: It's a game where most people end up mostly playing low level characters, and they made Sorcerers suck as low level characters. They simply have to wait too many levels to have enough resources to use their Metamagic frequently. Whatever defenses one can make for the power of a mid or high level Sorcerer, it is a slog to get there.
Monk Ki has the same issue as Sorcery points. 1 per level is simply not a satisfying progression for a class defining resource. If there is an original design sin of both classes it is this. It ends up too little at the beginning and a trivial limitation late game. Both also then try to make capstone abilities out of getting back what is, by then, a piddling amount of the points after you no longer really have need of more. The class progression charts have room to list how many points they get at a specific level, there is no reason it has to be so simplified. If we can handle an oddball progression of spell slots we can handle the same for Ki and Sorcery points. They could actually playtest what is a satisfying but balanced number to have at each level and have it progress accordingly rather than just decide that remembering an additional number other than their character level will probably break players' brains so lets just make it equal the character level and skip on playtesting.
But, for the Sorcerer, to me the truly indefensible decision was giving them Metamagic at level 3 rather than level 2. Nobody else waits that long to get something considered their absolute signature, character defining ability. Instead they get the ability to buy spell slots at a point where they only thing they are given enough Sorcery points to do with said ability is buy a single 1st level spell slot. The progression on Metamagic and Flexible Casting should simply be switched so that you start dabbling with Metamagic at level 2 and can start burning spell slots to power it further at level 3 (which is still plenty exciting as the level where you both get 2nd level spells and finally have enough spell slots to use leveled spells regularly).
Do Sorcerers suck? Maybe a little bit Mr. I-Don't-Know-That-Spell. I know you are really excited about the showy things you can do, but everyone else at the table would have been happier if you'd just played a damned Wizard. They were sort of coming around to you when you starting Twinning Haste, but then you lost concentration mid-battle and... it was bad. But really my problem with Sorcerer is less overall class weakness and simply that they have a slog through the first tier of play owing to getting Metamagic a level later than they should and having an inane and overly simplistic 1 per level Sorcery point progression.