Yaarel
🇮🇱 🇺🇦 He-Mage
A benefit of standardizing the subclass design space to four levels at 3, 6, 10, and 14:The more I deal with 5e, the less I like subclasses. Once upon a time you could just start play as an Assassin, or a Samurai, or a Berserker. Either through a separate 1-20 class or a Kit a 1st level character could take. Oh man, to be a Swashbuckler, I have to go to Rogue school for 2 levels, gaining the same abilities as the Assassin and the Arcane Trickster or a Mastermind?
Some subclasses radically alter the way you play a class, and others...don't really feel like you get much. You lose so much because WotC is terrified to make new character classes? It's especially bad when, at the levels most people end up playing at, you might only get those 3rd level abilities.
I mean, ok, fine, you could make the argument it's hard to balance new classes. But if balance between classes was important to most people, we'd still be playing 4e. And there's enough complaints about the way the game is balanced already for me to say, eff it, let's see Ninja and Cavaliers and Psionicists and Gladiators again!
Give people a reason to switch to your new books, WotC! So far? I'm not seeing much that you couldn't have shoved into errata or a "Somebody's Guide to Some New Stuff".
It is easier to decide if a concept needs a subclass or not. If it only takes two levels to cover the concept, it is almost certainly better as separate optional feats. If it takes six or more levels to cover the concept adequately, then it is to big for a subclass, and needs to be its own class.
Standardization helps use the various design spaces that are available, more effectively.