That's simple - all 2.4 Ghz systems use some means of frequency hopping, it is very unlikely that you will get any interference. That is what I meant by safer to use.
You are getting way off topic here, radios have improved because the technology has changed.
But to use your example - a newer car IS safer then any antique model. Safer for the driver. Doesn't mean the new car won't break down, it will probably have more problems then the older one.

And I'd probably change the potentiometers myself, rather then wasting money to have the old radio serviced. I stopped using 72 Mhz radios when I got massive interferences through a thunderstorm in the far distance. To each his own, most people never have any problems with their 72 Mhz systems.
I fly planes and helicopters, a computer radio with programmable flight modes and expo makes flying a lot more enjoyable.

Like I stated, it's my 2 cents