VAO and maybe more things that I don't even know about... I might be able to reimplement those in OpenGL ES 2 but I think OpenGL (ES) 3 is a good middle way between old stuff and over-engineered Vulkan, DX12 and Metal for dense but still ok performance and cross platform (mobile/PC) support.
Not yet with the open driver though. But yeah, its GPU is much more performant and capable of GLES 3, which the etnaviv driver aims to support at some point.
I guess you cannot expect from such a niche phone to compete with mass market products on price. That said, it's obviously a very individual decision if there's even a practical need for it.
I will try to get my Linux on DeX working first, S9 has OpenGL ES 3 and I managed to scrounge a dock and the app + linux image before it was lost...
How Samsung was thinking when they removed that project is impossible for me to grasp. They should have extended it to make linux run on the standalone S9 and they would have kicked Apple/Google in the nuts big time!
And a Sony Xperia with Sailfish OS? Or is it not FOSS enough? That might be. I bought mine second hand and spent the same amount as a Pinephone would be.
Trying to cancel the order, even if supporting the initiative would be nice, my 3D MMO needs OpenGL ES 3!