This guy doesn't appear to be a Twitch streamer. Aside from his rack having stickers for Go, Kubernetes, GitHub, and more, his Twitter description doesn't say anything about that.

If you're asking about in general would this be a good thing for a Twitch streamer... then I would say no. Mostly because most Twitch streamers are not going to know how to maintain something like this and they don't need all the servers.

If someone not so technical, Twitch streamers included, needed the redundant internet I would recommend something more along the lines of two ISPs like this guy (specifically over two technologies if possible: fiber and wifi, but that comes down to bandwidth requirements) but instead of going into multiple switches and having 3 servers running with VMs moving around just plug the two ISPs into something like the Unifi Security Gateway (USG) or USG Pro.