These newer cameras have crop modes. You aren't restricted to shooting 45 mpx. And CRaw is available for smaller file sizes...Everything is a compromise. Not everyone wants 45mp. I am not sure why some people have a hard time accepting that. If no one wanted 20mp class cameras then 1dx3, 1dx2, R6, A9, A9II, D5, D6 yada yada yada would not exist and if they did they would not sell. For some the only spec that matters is the resolution of the sensor, for others it is not a big deal.
That being said I will not get rid of my 1dx3 to get an R3 if it is 24mp. I was really hoping for 30. That way I would have 45, 30 and 20.