Steam is a set of tools that can purchase, download, and execute a variety of games and software, including Windows applications without the need of Wine via the Steam tool Proton. This can be a replacement for Wine although some applications might not work as expected. Most games are built for Windows but most work fine with Proton. It works on regular Linux distributions, including LFS without all the setup required for Wine.
As Steam is a complex set of tools that is capable of launching complex software, it depends on many tools, libraries, and graphics APIs to function and perform as it should.
Please check Steam Dependencies to find what you will need before proceeding, although most of Shared Dependencies is a straight shot. There is some choice involved such as choosing if you want ALSA or PulseAudio, X11 or Wayland, etc.