What do you believe HEVC is winning? The major online video platforms (YouTube, Vimeo, Netflix, Twitch, etc.) are all going to AV1.
HEVC had its shot but the terrible licensing stunted its growth and AV1 will replace it. Leonardo Chiariglione says the MPEG business model is broken and I think he's right:
http://blog.chiariglione.org/a-crisis-the-causes-and-a-solut...