Unlike earlier when camera companies tried to create mobile mountable bodies, looks like now the mobile companies are interested in this concept.
Xiaomi Modular Optical System - https://www.youtube.com/watch?v=BBuvc_K8tDg
Realme Ultra - https://www.youtube.com/watch?v=9VvFLYTF-8A
The technological advances are incredible. But I cannot help but notice that, with all that advanced technology on the taking lens side of the camera, there appears to be no attention to how it is that cellphone screens make for miserable viewfinders in bright light conditions, such as sunlight.
IMO, real, serious cameras generally have a good viewfinder which works well in sunlit situations.