SMS codes as mentioned and cellular data makes something with Sim card or e-sim a necessity. This can be mitigated by using a portable hotspot or cellular router/modem. Had a teltonika router that autoforwards the SMS as email.

Next best thing to GOS would be Calyx OS. Seems only pixels are getting full updates unfortunataly… https://calyxos.org/install/ The hardware on the pixels security wise is unfortunately hard to beat. Get a used one?

E/OS seems like a good choice if you don’t want to use a pixel.