Most old phones including rotary phones would be compatible with today’s phone system.
Basic phone technology hasn’t changed much in the last one hundred years, so that “candlestick phone” from the 1920s will work as fine as your cordless, and better in a power failure.
The only thing you’d have to do is adapt the plug from the four-prong type to the mini-jack now useda simple procedure using an adapter found in an electronics store.
Oh yeah, and touch-tone dialing would be out. We advise just sticking with your shiny new cell phone. It’s just more convenient that way.