https://www.pcgamer.com/adata-joins-the-5ghz-club-by-overclocking-a-ddr4-memory-kit-on-air/

Adata has become the second memory maker to achieve 5,000MHz on an overclocked DDR4 RAM kit without resorting to exotic cooling methods. Just as G.Skill did a little over two weeks ago, Adata used air cooling to break the 5,000MHz barrier, rather than liquid nitrogen (LN2).

Much of this comes down to theater, as neither company is actually selling a 5,000MHz memory kit. And even if they did, there would not be a whole lot of real-world benefit for users versus existing memory kits, like G.Skill's DDR4-4700 kit.