A leaker has provided further details about the Vivo X100 Pro+ or Vivo X100 Ultra camera flagship, which is expected to be launched in 2024. Based on a prototype, the triple cam equipped with 4.3x optical zoom appears to be quite versatile and can apparently reach ridiculous sounding digital zoom-levels.
As the article says, it’s marketing. If groups of 4 pixels are binned into 1, it’s really a 50mpixel sensor.
Yes, many of these phones won’t give you 200mp images (unless under a specific mode like RAW), so you’re always getting something more reasonable.
Pixel binning can help with low light (effectively doubling the light available if binning with the next pixel over), or it can help to extend the telephoto range, or it can pull details that’d be harder to get with fewer MP.
Most would probably argue that it’s better to have this option than not.
I think that diffraction limit effects already happen at 50mp cameras so tiny phone sensors would be worse. ( https://blog.kasson.com/the-last-word/diffraction-and-sensors/)
In this case, adding more pixels only slows down the camera without improving the picture.