I'm the owner of a Light Phone II [0] and (other than battery life), the biggest downside to the Light Phone I can envision for most people is the absence of apps like Uber, Apple Pay and Spotify. I think 5G isn't that necessary on a phone like that, except maybe for future-proofing.
This phone seems to have a camera, though, and access to Play Store (although it will likely be messy) really sets it apart from most "minimal" phones out there. Plus, a real keyboard might attract the people who despise the on-screen one on the Light Phone. They're really devices of different classes at this point, though. The price does seem awkwardly low, however.
[0]: https://www.thelightphone.com/