I'm saying that designing every class so that it's balanced when played as an at-will only class, but is simultaneously appropriate and playable as a daily-only class, and has a continuum of options that are playable and balanced in between, seriously restricts your design space.
That's not what I'm advocating. I don't want a monolithic design scheme any more than you do.
What I'm advocating for is for a recharge rate that is not determined by your class
, but rather by some other player consideration. A different place to make that choice, so that it does not come bundled with your archetype. Much like how 5e bundles skills and feats as separate from class abilities already. I'm advocating for a delineation that reflects how people actually approach the game.
There's little inherent to the idea of a fighter or a rogue or a druid or a wizard that mandates they have a certain recharge rate. Recharge rate is not a function of archetype. It is HEAVILY a function of playstyle preference, which means someone who wants to play a FIGHTER might want daily and encounter effects, or might find these effects repellent, and nothing about their desire to be a fighter decides that. Therefore, bundling one of these effects with the fighter class would be a mistake: folks would be saddled with what the designers thought a fighter should be, recharge-wise, rather than what THEY wanted the fighter to be, recharge-wise.
So recharge is not an element of class design in the way the game is actually played. Linking the two would be as big a mistake as linking feats to class design. It would tether them unnecessarily together. Not every fighter needs to be a Soldier and a Defender, and not every fighter needs to be at-will based, either.
So rather than bundle the class and the recharge rate, you should disentangle them, and let the recharge rate be selected at a different point, independently from your class, just as skills and feats can be selected independently from your class. It looks like their current thought involves it being selected at the level of picking individual spells, my idea just tweaked that to a round-by-round consideration, so you didn't have to have three different Magic Missile
This doesn't mean there isn't synergy. It doesn't mean that it won't come prepackaged "by default." It doesn't mean that if your class MUST have a certain recharge rate for some reason that you can't put one in there (though I'm struggling to see why archetype should dictate that).
It DOES mean that these choices aren't dictated for you by the designers. It means that if you want to be an Illusionist, this isn't defined by recharge magic (unless you want it to be).
I'm not seeing how opening that up mandates a certain design schema anymore than making skills swappable mandates a certain design schema.