I played Clash Royale for several days and the insistence on payments to progress was really off putting. The gameplay itself was quite addicting so I presume they're trying to avoid players burning out from binging. But the fact you either had to pay money or wait three hours to do anything of value was just too much to bear. The entire game design is genius in how it funneled you toward purchases.
Queue up chests to unlock
Earn "keys" when you win and your chest slots are full: Silver chests take 10 keys, etc. Still enables whales to spend their money, but makes it feel like you can earn *something* by playing.
I think even with this it would still be decently monetized, while increasing the feeling of player agency and engagement.