Things have changed, @LienRag . Godot 4.0 (currently) is using Vulkan only. The old OpenGL code is mostly removed/disabled. The developers decided to update to OpenGL 3.3 (but restricted to the OpenGL ES 3.0 feature set). This also means HTML5 will only be supported on WebGL 2.0. This will be similar to the current GLES 3.0 features of Godot 3.x. Some things will be better, but I believe some things will be missing, at least at first. You would have to have a really old desktop GPU to not have OpenGL 3.3 support. Anything made in probably the last 10 years or so will be fine. Vulkan is better, and will have more features, but you will need a better and/or newer GPU to use it.
If you are working on a project now, I would recommend sticking with Godot 3.x for the time being. Godot 4.0 is in alpha and is very unstable and unfinished. I did make some small projects with it, it works okay, but it crashes a lot and some things don't work. So I would not recommend releasing a serious commercial game with it now. The stable release is likely going to be next year. So your best bet is to stick with Godot 3.x for now, and just test the alphas to provide feedback, but don't port your project until later next year. You can also stick with Godot 3.x and use the GLES 2.0 renderer, if you need to support low spec or old laptops and stuff. Because Godot 4.x will have higher requirements.
That said, I'm building my game in Godot 4.0, because I think it will take around 1 - 2 years to finish, so it's a long term investment for me. If your game is smaller in scope, you don't want to risk using 4.0 (for example, if it's a 6 month project). But if you think you will be working on something for several years, maybe it would be worth learning Godot 4.x now. It depends on what you are doing.
