GIFs are quietly enormous
The GIF format is from 1987 and it shows: 256 colors per frame, no real video compression, and file sizes that grow ferociously with every frame. A five-second loop can easily outweigh a full-length HD video file per second of content.
Animated WebP does the same job with modern compression: the same animation at a fraction of the size, with proper transparency support. Browsers play it natively. If you’re putting loops on a website or into an app, this is the upgrade.