or maybe , can you on the export option add an option like "convert Face to vertex color"
or even simply auto convert vertex color to Face Corner when you export on gltf or fbx ... to be seamless for the user ?

for me too is more of a bug.
because on all 3D software when we deal with vertex color is ... a vertex color that it..
for me you add more confusion to the user, I am pretty new on blender (Thank you for this amazing software :) ) ..
for example, I still don't know how I can export the vertex color to Unreal.
i have made a bake material color to vertex color save the object on fbx , and when I try to reload the fbx on blender the vertex color is gone !
so how can I export vertex color on fbx ?