Now I’m curious why it hit general release at 3.2.

Any reason not to use SDL2? It’s stable, packaged in all distros and is not going anywhere for the next 10 years.

For those who don’t know SDL:

Simple DirectMedia Layer is a cross-platform development library designed to provide low level access to audio, keyboard, mouse, joystick, and graphics hardware via OpenGL and Direct3D. It is used by video playback software, emulators, and popular games including Valve’s award winning catalog and many Humble Bundle games.
SDL officially supports Windows, macOS, Linux, iOS, and Android. Support for other platforms may be found in the source code.
SDL is written in C, works natively with C++, and there are bindings available for several other languages, including C# and Python.
SDL is distributed under the zlib license. This license allows you to use SDL freely in any software.

Taken from the official website.