Those are usually quite expensive. If HDMI requires 48Gb/s capable transceiver chips to be built into every TV, they will get really cheap very fast. It might not be a viable solution in the end, but it could work for some applications.
If you mean switching, you don't need a switch for simply connecting two computers. Presumably that was the use-case supported by "HDMI-as-network-layer".
If you watch around, you can get Mellanox Voltaire rack switches for $200 or less. QDR gear is "obsolete" and often surplused at very attractive prices. Everyone else has moved onto FDR or EDR speeds.