There's plenty of different hardware out there but not a whole lot of reviews; and my experience with the HDMI interface has, on the whole, not been the best. HDMI is great for consumer stuff, and for plugging in a generic source to a screen (AppleTV, Firestick, Xbox, cable box, etc) -- but, as soon as you want to do anything even slightly more advanced, you often run into hiccups quite rapidly (EDID & handshake/negotiation issues, cable & port quality, HDCP, etc).
I have several 'screens' (TVs) and I wanted to be able to mirror my 'main' display to other screens on occasion, for instance. It's easy to do that with a cheap-ish "splitter" [though they are finnicky), but if you want to "scale" that at all then you rapidly run into proprietary and/or high-cost solutions or have to make substantial quality & capability concessions (and >=10G LAN connectivity is pre-existing).
I was annoyed by the lack of good options & and the extreme prices and/or the limitations of the options that do exist -- enough so that I'm working on (and already actively using) my own IP-based "video distribution" solution, heh.