I've been away from RCs for quite a few years and just getting back a bit into it with my son showing some interest. I've come to find out a bunch of my vehicles are discontinued but also a couple of my radios. I have KO Propo EX5UR DSSS radios and RXs. They always worked great for me and when I got back in a month ago I was looking for another receiver and found all the DSSS stuff from KO is gone. Don't seem to see much from other mfrs either.
So I'm curious what happened to make the mfrs abandon DSSS.

Under most conditions that RC cars experience, FHSS is less susceptible to interference than DSSS.

I can confirm that DSSS can glitch when some of the newer radios are near by. My M11 has locked on to a Flysky radio even when my M11 was closer to the car. Add to that the lack of receivers out there and it's probably time to move on.
If I didn't have 4 cars on my current radio, I would have already bought a 4PLS.