alt Hacker NewsIt's pretty clever optimization, it actually only shows a few dozens images at all times and only update the groups as you zoom in, for example https://tiles.onemillionscreenshots.com/2024-05-01/tiles/-1/...
You don't even need something fancy like WebGPU/WebGL, just the CSS transition property will do the job there.
It's "just" Leaflet but that's how all map libraries work. Super easy to implement and it can be used for much more than just maps.