My family has a Sony receiver bought in 1966. It works great with sources from phonograph to smartphone. There is no feeling of anything disappearing, on the contrary it is a device which is extremely pleasant to use and otherwise unthought of. Tuning its radio using a heavily weighted and lightly damped knob is faster than digital, the power-on latency is a few milliseconds, and most sources can be selected with a single press instead of scrolling an endless, feelless knob like many modern models.

Who is making receivers now that people will enjoy in 2073?

Are you suggesting RCA jacks are getting phased out? That's the only way I need to worry.

I went to a small record store just the other day and they were selling fancy brand new turn tables that I could have bought. They also had a bluetooth module, and even a very fancy device that had 2 RCA connectors on one end, and a 3.5mm jack on the other so you could plug up something called a "phone" without even spending all the money on wireless. It's amazing how audio, for the longest time, just worked and I didn't have to think about it. When you keep things simple and standardized it pays dividends for years.