Yes. You're absolutely right. Because the only use for a WLAN is using the internet...

Actually it isn't. By far! 1. On a gigabit wired network you get 1Gbit of transfer speed. There is a very small percentage lost to coding but you get well over 100MB/s (up to about 120MB/s) trough a Gbit connection. If you get slower speeds and don't know why, than start searching for the bottleneck! 2. The 400Mbit to 800MBit in a WLAN is the "wire speed". I've never seen transfer rates that are more than 70% of this. So, I expect to get maybe 56MB/s (which is already quite good) out of "GBit WLAN" while I get 120MB/s out of an Ethernet connection almost all the time. Still impressive how they even reach such speeds! That's engineering at it's best!