I don't know if I like the direction they are going there tbh.
Keep in mind this is what, 5 months from now, minimum? I don't think it's that crazy to think that even F2P players can have obtained all of this stuff by then.
And it's not really an easy problem to solve if you think about it. I was already thinking about this even before I found out this Dragon Buster thing, and say they release something down the line which obsoletes your ascended units. Do you just throw your ascended unit away? Use it for limit break fodder? That's such a slap in the face. Considering how much resources it takes to make one, it should *never* become obsolete. At the very least, it should be required in order to get the next set of upgrades. Otherwise it's such a punch in the gut when you waste all those resources on them, and 3 months later it's as useless as a non-ascended SSS.
So I kind of agree that it's important to make the ascended units important long term, even if that means they are a special kind of food required to obtain some next tier of unit.
Also, if you notice as time goes on they get more generous with rewards. Every F2P game is like this. When the game is new, they are stingy, and as time passes, things become easier and easier to acquire. You can already see this in Dragon Blaze. The first 28 day login bonus was 1 S unit. After that it was 2 S units. This month it's an SS unit. We find out tomorrow what the August one is going to be, but my money is on 2x SS or a single SSS unit. Watch, I'm calling it now. Then we have the guaranteed SSS for the $99 package.
Even if you're totally f2p, the point is that as time progresses, it will become easier and easier to obtain the higher level fodders. I wouldn't be surprised if you can get SS from ally encounters in Korean version already.
In order for these games to have longevity, they have to remain accessible to new players. And imagine if some guy comes in 6 months from now, trying to get one of these dragon busters, and he needs to get a legend, angel, and boden (whatever that is) to get this dragon buster. That's probably 30 SSS units, and if it's not SIGNIFICANTLY easier to acquire SSS by then, the game just dies.
Anyway, power creep is a thing in all of these games. I wouldn't worry about it. What I would worry about is them implementing power creep in such a way that your advantage now does NOT translate into an advantage down the line. It's a suicide business model, because once that happens the only people left are the whales, and the game's over.