As a Gen-Xer who used to twitch with the best of the younguns, I can vouch that we're playing a lot fewer games that require reflexes that can't be made up for with strategy and treachery (e.g. exploits).

Mostly I play dad games like Satisfactory or Subnautica but do pretty well for my crew in Deep Rock Galactic

If a boomer shooter is a classic run-and-gun shooter (contrast: tactical shooters or first-person survival) I'd still do fine unless its bullet hell or something. Serious Sam had the tendency to teleport in dozens of shooters on a plain with no cover, or send me into a dark place teeming with climbing ninja monkeys.