Zoom and Facebook Portal are still just trying to make meetings marginally better with a dedicated device. We're going after a different niche where teams need to actually feel like they're in the same room with an always-on call.
We talked to a bunch of teams that tried this. It's really hard to get people into the call at the same time. Eventually, there are enough bad experiences of being alone that people stop using it.
Sidekick's features maximize the chances you're not alone. Some examples are outlined in the original post!