KNX can be used over wifi, it is both a protocol and a wiring standard. Many KNX devices are not wifi-enabled however, which means you still have to use some wiring to connect things. I agree KNX is not good enough, even if it's the only home automation standard worth anything. The biggest problem however is not the wiring, which is preferable to wifi due to the reliable connectivity, but the consortium-made KNX ETS software. You use that software to change the configuration of your devices, it has no alternatives, and it is absolutely horrible.

Anyway, if all those IoT smart home vendors would just implement KNX support, and a group of open source developers would get together to build some proper management software to replace ETS, it would stand a chance. It at least has the benefit of being an ISO standard and having lots of device choice in the market.