Probably because it's quickly becoming the only reasonable option on mobile

GrapheneOS has an official partnership with a large OEM (Motorola), has near perfect app compatibility, is constantly improving upon user experience, and has been well known and regarded in the privsec community and by many trusted security experts. It appears to be gaining more mainstream awareness as a result.

Oh, and Android 17 has been released so there is hype for that.

Sort of, there're more posts about graphene in the year 2026 & they get much more attention. Aggregated some data and plotted it with my agent: https://boop.icu/Pr.png