XVC is one of many compression codecs that are unproven and unimplemented. At the moment the only option in reality is HEVC since that is what is built into all of the TV's. It doesn't matter how good a codec is, if it is not implemented in the target devices you cannot use it. Unlike a computer, on TV's you can't download updates from the web, the manufacturer must implement the decoder and issue a firmware or OS level update.

Latency of networks is unrelated to compression.