I recently installed a mobile game (Star wars galaxy of heroes) for the first time in years. It's a game I already played then dropped. There are literally 11 different layers of grinding now(though admittedly with a degree of overlap and automation).The most egregious part is the prerequisite for special characters. It forces you to go through the whole process 1-5 times just so you can do it again with who you actually want. Then you can finally use them. It really is just a grinding simulator disguised as a game.
Only reason I'm not dropping the game immediately is the actual endgame might be fun now and I have a bunch of characters already so I can actually enjoy myself without the grind if necessary.
But man, it is infinitely better to learn a skill like programming or art than it is to download mobile games. Far better use of your time and way cheaper.