It may or may not help but my 66 Strato Chief was like that. I pulled the door panels off, cleaned up the tracks that the window rollers are in and greased it all up good. I would say that effort to roll them up and down is 75% improved. They are maybe still a little stiff but really really easy compared to when I got the car.

Usually the problem is the white grease that the factory installed has turned very hard and is dried out, removing the lubrication that is supposed to make it all work nicely. It takes a bit of time but it's one of those jobs that is very rewarding when it's done!

Just doing my 64 Beaumont and will reinforce what Carl said.
If the plastic rollers are broken it can cause jamming. They are available.

ya, i would take everything apart, clean off all the grease,  brush out the channels, lube everything and reinstall.  i bet they work fine after that.  unless you see some obvious wear on some pieces during disassembly

I used this company a few years ago and was able to get the unobtainable stuff from them. Might help if you get stuck...

www.ebay.com/str/Altha-Fastener

Cliff