I don't count any UA option older than a year or that has appeared in a book as a viable sub-class to pick for one reason or another, so I don't subscribe your "well over 100" count.
That being said, there is a lot of room in 5E to expand both mechanically and narratively. I am very anti-conservative when it comes to what should be in Fantasy. Fantasy means fantastical, and just because something was in Tolkien or was in old school D&D doesn't mean that's all there can ever be. The idea of Barbarians having Wild Surges, Rogues being revived from the dead, and Warlocks making pacts with krakens all highly interest me. I want to see fantasy expand further, faster, and to reaches hitherto now never seen.
So yes, I want more. I've homebrewed my own options, and playtested them for years now. I've made some classes just for fun (Shinobi), to remix a common idea (Necromancer, Warlord), and to come up with entirely new concepts (Flesh-Eater). I plan on making more classes, and more sub-classes too. I've made Fighter archetypes (Veteran being my favorite), Sorcerers, Warlocks, Bards, and more. Though a lot of this stuff will never be published, I try my best to put it out there so that people will see that 5E need not be limited to Battlemasters and Thieves, and that the sky is the limit for classes and class ideas.
Of course, there is a limit for any system officially. The 3.5/PF era proved that no system is immune to the danger of buckling under its own weight. But 5E is not even close to that limit yet; not even half-way there