I find plex to be quite buggy and opaque. It is tolerable for the few things that it does, but that's mostly because it's a niche, and there isn't that much competition in this space. I don't know how emby is doing these days.

>trying to expand with features

Their expansion efforts are also not that scalable, again because they can't control content. They recently added integration with tuner boxes and dvr, but that whole segment is on its way out. Not to mention, various other issues with the inability to handle DRM and other copyright restrictions that come with cable. They also tried some cloud drive integration, which again didn't pan out, because they don't control the storage. I think they've tried to bundle some news and podcasts, which is marginal at best. In this space, I just don't see how you can make money unless you are selling content, storage or compute. Plex sells none of these. At the end of the day, it's some glue software that probably calls ffmpeg to transcode.