TLDR: Why do so many routers support >1Gbit/s on their WiFi while only having 1Gbit/s ethernet interfaces?

So, I’ve been upgrading parts of my home setup and have a router (without AP) that has 2.5G interfaces. My PC also has a 2.5G interface, but that only going to the router is kinda useless (the ISP offers 1G).

The place my PC is at is also a good position for an AP. So, I went looking for a cheap second hand wifi router and stumbled upon quite a few that were boasting >1G connection speeds, not only AX but also AC. Now I know this is often a combined theoretical Max, but still a lot offer >1G for the single band.

The vast majority of these routers, though, have 1G Ethernet ports. Putting that between my PC and router reduces that linkspeed and I can’t actually reach over 1G for the WiFi devices as well. Why would you sell a product like that. Undoubtedly those radio’s were more expensive but their in a package that can’t fully utilize them. I can think of some reasons: marketing, radio’s are mostly not fully utilized anyways, helps with latency, maybe?

Does anyone know why it’s done like this?