I supported the Shadowcast back when it was in crowdfunding and have been using it for many different cases. It's simple plug-and-play, easy to use, and works both as a video input or can be displayed through their app!
Streaming on Twitch: Can be captured as a video input source or you can directly capture the Genki Arcade app (I capture the app, it provides additional settings like mic input and can be easily resizable.
Streaming to friends on Discord: Same as above, super easy plug and play.
I also use it as a capture for my GoPro whenever I'm not streaming my Switch. It's probably the best solution out there for a cheaper camera capture.