Review Suggested Edit

I'm about to build a desktop PC first time in many years and I was confused by the following discrepancy related to memory speeds:
- Zen5 CPUs "natively" support DDR5-5600 RAM (for example [9600X](https://www.amd.com/en/products/processors/desktops/ryzen/9000-series/amd-ryzen-5-9600x.html))
- even faster DDR5 modules are available, I have seen at least DDR5-6400

Yet motherboards, even with the newest X870E chipset support only up to DDR5-5200 "natively" and require overclocking for higher speeds (for example the currently most expensive Gigabyte model [X870E AORUS MASTER](https://www.gigabyte.com/Motherboard/X870E-AORUS-MASTER/sp#sp)).

So my first question is what are the possible disadvantages of setting a motherboard's memory bus to an overclocked speed that is "natively" supported by both the CPU and the DDR5 modules I intend to purchase.

The second question is why is it so? What stops motherboard producers to "natively" support speeds that already are already "natively" supported by CPUs and DDR5 modules that these motherboards were designed for?

PS: I put the word `natively` in quotes as I'm not sure if it's the right adjective to describe the speed at which a given component works without overclocking.

**Update:** specs from other manufacturers have been recently published and many of them do support 5600 "natively" (for example [MSI Tomahawk](https://www.msi.com/Motherboard/MAG-X870-TOMAHAWK-WIFI/Specification)).