Either only Fortnite, or a mix of that + Minecraft + Roblox.

Nah, zoomers went through the whole indie horror game gauntlet, Minecraft, terraria, etc.

Edit Addendum: Also, don't forget about games like Friday Night Funkin and the plethora of mods that it spawned. The Five Nights at Freddy's fandom was basically a cult at some point and still memed. Cuphead was a big enough phenomenon to get it's own animated series. Stardew Valley is another game that will doubtless have influence beyond it's years. Motherfucking Undertale, sans memes, etc. VA-11 HALL-A was pretty popular for a while too. Don't forget about Among Us. Lethal Company is still getting updates. SCP Secret Laboratory is another one people forget about, but is still a game with a dedicated player base. Kenshi...oh man great game released in 2018. Fucking Persona 5 and Metaphor ReFantaszio, great games. MiSide is a new game, a horror game that doubtless has a small yet dedicated following. No Man's Sky is great, especially after they fixed it. Many Gen-Z doubtless remember Subnautica. Ultrakill is something that is quite special.

I mean, they've decided to stick with fortnite, roblox, minecraft, whatever. But, there have been thousands of great games released that they just chose not to play.