Mobile phones in the era before smartphones had cameras, email clients, games, music players, and even web browsers. They just weren’t very good at those functions and their core feature was being a phone for voice calls. Texting was barely a feature on some of them (the first camera phone in the United States, the Sanyo SCP-5300, didn’t have a two way text messaging client - the user had to go to a website on the phone to send texts, which was inconvenient even on a 1xRTT 3G connection.)
The e-ink phone seems closer to a dumbphone than a smartphone, IMO, largely because it lacks access to an app store.
Source: I sold mobile phones before smartphones and during the early smartphone years (BlackBerry and Palm Treo, for example.)
Edit: calling it a feature phone instead of a dumb phone might be more accurate.
Linux is a lot, lot, lot easier to use now than the 90s.