DDR4 equalled epic fail if we are honest as it is hardly better than DDR3 performance wise.
I remember 8 Pack posting a load of bench figures on another forum when DDR4 arrived to show how fast it was. I think I was the only one at the time who pointed out his scores where hardly better than if he was using DDR3.
DDR4 = higher MHz but terrible timings, will DDR5 be even worse.
And finally matching the numbering used in GPUs for a while. It was very confusing (for me at least) why GPUs were using GDDR5 when PCs were still on DDR3/4. I know I know GDDR has nothing to do with DDR but still they are both DoubleDataRate memories so the confusion to me was how come one is on the 5th iteration while the other is stuck at 3rd/4th?