DDR4 didn't have much over DDR3, just a bit of bandwidth, and most apps weren't that sensitive. However DDR5 doubles the number of channels vs DDR4, while also

DDR4 didn't have much over DDR3, just a bit of bandwidth, and most apps weren't that sensitive. However DDR5 doubles the number of channels vs DDR4, while also having a higher clock rate (more bandwidth), so it's a bigger difference.