yeah, Ive never seen an h265 only camera.. many still support MJPEG still, so you can expect to maintain that compatibility for a good long time to come.
new formats take time; especially HD formats as they pretty much require hardware acceleration with the high levels of compression used.. as that hardware becomes more ubiquitous then the video will start coming in.. my new AndroidTV supports h265 4k HDR, im sure many tablets/phones will soon.. its becoming standard on the current generation.
my h265 cameras support h265 on main stream and h264 on substream (or vice versa), so you could record it even if you cant remotely display it in real time.. so we do have that going for those of us whom dont buy new phones/tablets/computers every year.