This sort of thing is quite different technically.

With Inkscape, blender and gimp - the main draw is an extremely complicated UI that produces image files. A social network is just sending text around back and forth.

The beauty here is the activitypub spec. The way it works is like:

ActivityPub Protocol <- Lemmy Backend <- Lemmy Client

Building a replacement backend or client is comparatively trivial. Making a good one would be hard, of course, but a single developer could whip up something that's technically a lemmy client, or technically a activitypub backend over a weekend.

That decoupled layering, the idea that each bit just does one comparatively simple thing, is intentional.

If lemmy/kbin catch on (which it looks like they are), it will be not long at all before there are a a plethora of tools and clients cross platform.