@Lilliwyt It really depends on the game. I've played
Kirara Fantasia since launch and not spent any money on it. Until recently that didn't feel like a problem, as the game is pretty generous with free gems. The problem at the moment is that I've run out of sources of free gems (all my girls are max friendship bonds & only a few aren't evolved) at the same time they're cranking up the quantity of gachas. But from December 2017 until now it was fine. Getting in at the start helps as well, since most gacha games take a while before they really crank up the gacha volume.
It takes self-control and patience though, I've missed out on many girls I want to have (seasonal ones in particular) and had to wait months after release before I got others. On the flip side, I've gotten a few girls I wanted badly at their release as well, so it balances out.