OpenGL 4.5 has named objects which makes working with OpenGL feel less archaic. Also 3.3 version doesn't have tessellation shaders. But for some reson OpenGL 3.3 is still being called "a modern OpenGL".
For a while it used to be that OpenGL 3.3 was the only modern version you could guarantee to find everywhere, even on crappy hardware and actually work without major issues.
No idea how it looks like in 2021.