Not sure, but they were able to get Wayland support working out of the box in this update. Previously it required workarounds, and even with workarounds, new issues would pop up in a game of whack-a-mole, and nobody really cared because running MC in XWayland was good enough for most people. Whereas SDL3 has very solid Wayland support out of the box. Minecraft only really uses GLFW to create the window, set the taskbar icon, go into fullscreen mode, and accept input, with everything else being handled by raw OpenGL, so this was an easy switchover. Now that Minecraft supports Vulkan, it's able to use a fully modern stack on Linux desktops / Steam Decks.

> I'm always wondering whether or not SDL would be better

SDL supports mobile; GLFW doesn't. Maybe they're unifying codebases between the platforms.

Edit: BTW SDL3 still works even on Android 4.2. I made an app using it and ImGui, without any Java.

For one, input method editor support.

SDL is more of a "platform" you can use anywhere. It includes literally everything you'd want from the OS layer (windowing, graphics, audio, input, network code, threads) whereas GLFW is just windowing, graphics context and input, you need to bring your own audio, network code and threading library. Not a big deal for some but SDL does do more... Plus it's even more portable than GLFW.

You could make an entire 2D game using the SDL API without OpenGL/vulkan.