I disabled local thumbnail generation almost a year ago, and things mostly work the same.

Instead of a local thumbnail image URL for things like news articles that get posted, it will be the direct URL value from the og:image metadata from the source. Usually those load fine, but sometimes they don’t due to CORS settings on their side. Probably only 1-2% of posts have issues, though.

For image posts that come in via federation, (memes, pics, etc), the thumbnail image URL is the same as the post URL. In other words, you’re loading the full res version in the feed. Since I use a web client that has “card view”, this actually works out better, visually. YMMV whether that’s a drawback for you.

The only pitfall is that you will lose thumbnails for image posts if an instance goes offline or shuts down.

I’m sure that does increase load slightly on other instances, but no more than if the remote instance had image proxying turned on. And the full-res version always has to load from the remote instance (even if you have local thumbnail generation enabled). All in all, I’d say the additional load is acceptable given the benefits of disabling local thumbnail generation.

To mitigate that, in my case anyway, I have my own image proxy/cache in place. My default UI is Tesseract and it’s configured with the image proxy/cache on by default… (I think I saw that Photon is also working on something similar). In this configuration, the first person to scroll past a remote image fetches it directly (via the proxy/cache) and it’s now available locally in the cache for everyone else (unless they’re connecting with a different client that doesn’t use Tesseract’s proxy). Granted, I shutdown my instance last year and it’s just now a private testbed for development, but when I did have daily active users (plural), the proxy cache helped.

Now the only images my instance stores are ones that are uploaded locally.

Why did I disable local thumbnails?

• I closed up my instance and didn’t want potentially problematic thumbnails being generated while I wasn’t actively modding it
• Generated thumbnails go in, but they don’t go out. There’s no way to clean them up later other than the ephemerally generated ones (if someone requests a version in a custom size, for example)
• Increasing storage costs. Like, I’d be scrolling the feed and see some of the dumbest shitposts while constantly thinking “Ugh, this is costing me money to store a copy”.