Beneficial yes, practical no.

Beneficial because Reddit captured a ton of niche communities that used to exist on forums/usenet/etc, and there’s a lot of actual unique, useful content buried under all the noise. Ideally that content would be able to filter back into places that aren’t tied to some startup that never figured out how to be profitable.

Impractical because I imagine quite a few servers would have to defederate because they simply wouldn’t be able to manage mirroring the constant stream of stuff coming out of Reddit. It’s a bit early to tell how long any of the general interest reddit-a-likes can sustain on donations or whatever, and turning on that firehose would transform some hobbyist servers into money pits fast.