It gives OEMs versatility and motherboard manufacturers options. TBH, motherboards will support one or the other, and I don't see many motherboard makers supporting DDR4 in the DIY market unless there are benefits for doing that.
At this point in time its all about the money for me. Who cares about specifications being beaten to death here. I did extremely well with AMD stock in 2020 and now its time for Intel in doing me a "short-sell" favor or lift as well. Once the real cash rolls in it will take care of the specifications and then some. See you for a show and tell during Intel's 4th quarter earnings call in early 2022.