Id say the difference is the newer cpu. 5000 series is gonna have a much better memory controler than what came out when 3200 was considered fast. Im sure once we get a few new cpu gens with new architecture, then 4 sticks of 6000mhz will work pretty easily, too.

3200mhz is pretty average performance, and I would expect most kits to be able to do it even with 4 sticks. When you get to the high/excessive performance 4100mhz+ ram kits that tax the memory controler more its very unlikly you will be able to run 4 sticks, however you could get lucky still. Same with ddr5 6000mhz. You could get really lucky and have it work, but it’s not a guarantee and more than likely wont.