I play Arknights and have fun, but it sounds like you don't want to play a mobile game. It's pretty reasonable to play as a f2p account. Everything can be cleared by lower rarity 3*, 4*, and 5* operators and 4* operators are easy to get. The 6* gacha operators are good, but they're mainly for quality of life and you can go far with just 4* ops. It doesn't spam you with microtransactions ads or anything. Story is pretty good if you like visual novels. The anime cringe stuff is pretty minimal and the operator designs are really cool and neat.