I doubt this permission prompt would include implicitly cached content (the browser would just clean up the oldest stuff). Unless the site is explicitly downloading and caching video I wouldn’t expect that to count.
Quite possible that there is some sort of storage leak in the frontend.
There’s no reason to use anywhere near that much storage browsing Lemmy.
If they’ve somehow ended up caching a lot of videos and pictures, I could see it happening. I’d try clearing the cache, see what happens.
I doubt this permission prompt would include implicitly cached content (the browser would just clean up the oldest stuff). Unless the site is explicitly downloading and caching video I wouldn’t expect that to count.
Quite possible that there is some sort of storage leak in the frontend.