Loading.io (pretty basic and cheesy)
The GitHub globe, article from their team here. And of course this is one of the first lines: “At the most fundamental level, the globe runs in a WebGL context powered by three.js.” This thing is so much more in depth that I thought it was.
More SVG animations here, not necessarily bg images.
The AnimateMotion element
The mpath sub element
Sarah Drasner is the authority in the SVG animation space. Relatively recent video here to watch with time.
SVGOMG (SVG compression)
GSAP (greensock), Framer Motion, React Spring, D3.js, SVGator.