As someone who's trying to regularly promote the Threadiverse on Reddit, most of the potential new joiners are already overwhelmed with having to choose an instance, so adding another choice between two platforms will just stop them even earlier.

Regarding the choice of Piefed, it has quite a few features that Lemmy doesn't have:

• multicommunities
• onboarding process asking new joiners what they are into
• crossposts comments consolidation
• communities moderation features
• posts and user flairs
• keyword filters

https://join.piefed.social/features/

Lemmy should get there in version 1.0, but they still don't have any precise timeframe for that release, and still need to do some testing https://lemmy.ml/comment/23570258

You might see a few people discrediting Piefed for some optional filters it offers, but all of those filters are configurable by admins and disabled by default: https://piefed.zip/c/fediverse/p/1005977/piefed-admin-settings-that-allow-to-enable-or-disable-content-filters-they-are-disabled-by