That just made me have a realization (probably a novice one). When people refer to the "works on my machine problem", it is probably mostly about machine config

That just made me have a realization (probably a novice one). When people refer to the "works on my machine problem", it is probably mostly about machine configuration and installed programs, not the choice of OS entirely! As a lot of people have said, Docker still has portability issues between e.g., Windows and Linux.