You can get laptops that have 5G radios that you can use for data with Linux.
As I understand it, there’s no support for voice/SMSes at the radio level, but in theory, if you were willing to tolerate it and your cell service provider offers support, you could do WiFi calling.
Could also get service from a random other VoIP provider, use that over the data connection.
Probably not as battery-efficient, requires more of the stack to be awake to be listening for incoming calls.
I think that a larger downside is that Android software is designed for a touch screen and low power usage and low data usage across the board, and GNU/Linux software generally isn’t.