Completely putting aside the 'game devs are a business and are out to fuck you over' mindset for a moment, from a purely business perspective it makes close to little sense to drive away your freeloading playerbase. There is close to zero point for someone with too much money to spend to spend it on something akin to a deserted island without an audience. You rarely, if ever, see any successful, long-lasting mobile game that doesn't have a sizeable non-spending playerbase; as a close example and arguably a spiritual predecessor, Granblue definitely doesn't have 22 million spending players.
For any given playerbase, the more the numbers shrivel up, the more the business model has to go harder on the big spenders, which then feeds into the loop you're talking about where free players actually do have a compromised experience, leave, and it becomes a critical-mass feedback loop till the game in question folds. Gacha games are also definitely in a mature enough state in terms of business and market R&D that many devs can see this coming in the early stages of a spiral.
In other words, pragmatics aside people aren't dumb and will find better things to play if they feel they're having a compromised experience.
Not saying it doesn't happen here, especially for the unlucky ones who get completely screwed over by the gacha (without recourse outside of waiting for months for another chance at weaning meaningful progression out of an uncaring slot machine) but it's all checks and balances.
Anyway, that aside, what's again interesting to me is the revenue-per-player which is inordinately high compared to other similar games in the market - what Dragalia doesn't (currently?) have in sheer numbers it seems to make up for in fanaticism.
For comparison PAD's $12-per-player average was shockingly high in 2014:
https://www.forbes.com/sites/insert...s-its-closest-mobile-competitor/#615ba6ad3e86