this. our TV (a few years old, "smart") can play videos from a network drive, but doesn't support H.265. reencoding a season's worth of episodes to H.264 takes a while...
That didn’t stop, of course, but I generally don’t notice the improvements if I’m not looking for them. Someone with a 4K or better home theater will 100% benefit from newer codecs’ many improvements on all those extra pixels but if you’re the other 95% of people watching on a phone or tablet, lower-end TV with the underpowered SoC the manufacturer could get for $15, etc. you probably won’t notice much difference and convenience will win out for years longer.
One area where this can be important to remember is when comparing codecs: a fair number of people will make the mistake where they'll take a relatively heavily compressed video, recompress it with something else, and get a size reduction which is a lot more dramatic than what you'd get if you compared both codecs starting from a source video which has most of the original information.
Even though x264 quickly started seeing better results compared to DivX and XVid, you didn't see pirate encodes switch to x264 for years.
So it was kind of a magical codec upgrade and now it seems more incremental to me.
Encoder maturity is also a big factor: when H.265 first came out, people were comparing the very mature tools like x264 to the first software encoders which might have had bugs which could affect quality and were definitely less polished. It especially takes time for people to polish those tools and develop good settings for various content types.