If you want pure-play Linux, there's Purism (PureOS), Pine (PineOS), SailfishOS, Ubuntu Touch (33 supported devices, including Fairphone, Xiaomi, Google Pixel, and Lenovo, amongst others), Tizen, Mobian (based on Debian), and postMarketOS (based on Alpine Linux).

If you want an alternative to the iOS / Android duopoly, and will accept AOSP (Android Open Source Project) or de-Googled Android, there are AOSP devices (including KaiOS), GrapheneOS, LineageOS, /e/OS, LightOS (Light Phone), and a number of feature phone / dumbphone OSes including System30+ (S30+), OpenHarmony, and a few others, see Wikipedia's list: <https://en.wikipedia.org/wiki/Mobile_operating_system>.

Practically, I'd suggest a feature-phone plus either a small laptop (far more capable than iOS/Android), or a tablet/phone running GrapheneOS or LineageOS, possibly one of the full-featured Linux OSes above. Google Pixel is ironically amongst the most viable non-Android hardware devices, with Fairphone and Purism being my next-strongest options. Apparently Lineage is now supporting Samsung's Galaxy series: <https://news.ycombinator.com/item?id=49339930>, and GrapheneOS Motorola support has previously been announced, though remains pending: <https://motorolanews.com/motorola-three-new-b2b-solutions-at...>.

I'm not sure which of these include bundled AI, though I suspect that that's going to be coming to more platforms, absent AI backlash which seems to be swelling presently.