My point is that GLVND is marginally useful but neither significantly helps nor hinders the work that is needed.
I'm not talking about libglvnd usefulness for your work. It is relevant to you in a sense that you have to support both libglvnd and legacy configurations, whether libglvnd is actually useful to you is not for me to decide.
From the perspective of FreeBSD project, what does GLVND accomplish?
Libmap overrides are static, while libglvnd selects appropriate OpenGL implementation dynamically. That doesn't seem like much, but once you actually tried to explain to multiple people why OpenGL applications break on Intel GPU with nvidia-driver port installed (with zero success rate in my case), it's pretty clear that this functionality is indeed necessary.
430.40 needs libglvnd somewhere; it doesn't have to be /usr/local/lib/libGL.so.1.
Yes, I know that, otherwise I wouldn't refer to nvidia-driver shenanigans.