Sure, but OpenGL itself is still useful and used in modern software.
Not to mention GL is a massive and gigantic kludge/bloat compared to vulkan (mostly due to the glsl compiler). So this is good to let it go.
GL is only deprecated on Mac from what I understand.
I humbly don't think I am the right guy for that: I use raw x11, and will use raw wayland once the steam client is finally and actually wayland enabled, even though I may do the jump before... because "valve": their "pressure-vessel" is buggy, and I am helping fixing alsa support in SDL3, all that is starting... namely if I code something GFX related that would be more a wayland compositor on drm(dmabufs)/vulkan, probably based on valve one, either in plain and simple C (compiling with tcc, cproc/qbe, simple-cc/qbe), minimal to 0 dependencies without the latest ISO tantrums, or x86_64 assembly (before a port to riscv in the far future).
But never say never.
>It is legacy and started to be retired.
The standard itself, but the implementations are still being maintained and new extensions are being added. It is still a solid base to build upon.