The device referred to in the article gave me the idea to buy/make such a lightweight device with which you can surf the Internet, chat via XMPP, use e-mail, bu

The device referred to in the article gave me the idea to buy/make such a lightweight device with which you can surf the Internet, chat via XMPP, use e-mail, but at the same time receive calls and SMS. Also the device needs to run for a long time (ARM?) Sounds like something that can be done on a Raspberry Pi, but I'm not sure. It would be a good replacement for the phone, to be honest. It would be possible, of course, to take a simple phone for calls and SMS, but I recently read an article about the fact that such phones can have backdoors. In general, it would be cool to refuse calls completely, but unfortunately there are people who do not have other options. Besides, I go to places where the Internet does not work. In general, are there such devices in the real world that meet the above requirements?