Actually the 30 year old boomer is usually associated more with 90s and 00s era games like Doom, Quake, and Unreal Tournament ("that 30 year old boomer that likes arena shooters"). The "zoomer" is associated more with stuff like Fortnite.

The whole joke with the 30 year old boomer is it represents older millennials who, despite still being far from middle aged, behave almost no differently from a middle aged baby boomer (being out of touch with modern youth culture). The "zoomer" meanwhile represents the current young generation.

This, but ironically.