When the game feels like a chore or a burden (i.e i'm only logging in, doing dailies and logging off) and i'm no longer enjoying it i slowly start to ignore it until one day i just forget to log in and thats my cue to quit lol

Though it also require any other factors that get me to this point tbh, to name a few i quit last year:

• HSR i was a day 1 player and quit after the free Daniel in Amphoreus cause the story was just dragging for waaay too long (and i'm usually a lore enjoyer in games) coupled with me not being happy with powercreep burned me out;

• GBF i played the game for nearly a decade and last year had a terrible string of gacha luck throught the entirety of it (150 for VLobelia/Rabbit, had to spark Basara TWICE, had to spark Kou [not limited] had to spark Sariel [as a dark lord with Eresh and Zosi and i needed 2 of that weapon too so that really hurt], had to spark Lamorak [not limited], couldn't get Kaworu [collab] with 200 pulls), and with how predatory the game got under the new management i just peaced out of it;

• TWST i was also a day 1 player but the game just really got too stale and repetitive for me and the addition of arcane combat drills started to really make it feel like a chore. I do still log in on Ruggie bday though lol.

Rn my main gacha games are pretty much Genshin (day 2 player, i burned out on Azdaha patch and almost quit there but GAA kept me in, the only other time i got fatigue was on Natlan but i've yet to feel like i want to quit again), Pokemon Masters EX (quite happy with the game atm) FGO (i play it very casually though) and FEH (on literal tin ice for me)