While I might agree that wired will normally be more reliable - if you have a reliable system, then it doesn’t really need to be “more reliable” and I think it’s not really right to blame the technology when (as is normally the case) it’s often us humans who are to blame…
Just like wired solutions, wireless solutions need some planning to understand the network. With a wired system, this happens - it has to or you don’t have any connectivity. With a wireless system, this often doesn’t happen - people tend to plug things in without really thinking, and then complain when it doesn’t work well and either blame the software, or the technology.
I worked on the Hilton Hotels ConnectedRoom system. In the hotels we were testing in, there were hundreds of rooms - all served with 2.4GHz WiFi, BLE door locks, and ZigBee for lights and thermostats. This worked very well (ie reliably), and I think it would be difficult to think of a more congested place (RF wise).
If you’re building a new house - wire it with CAT-6 and be done with it - it has to be best for sure. However, wireless will just as work well if some thought is put into it, and you understand what you’re doing and how RF propagates etc. and it’s usually easier to install into existing buildings than a wired system.
What I would say though is doing “half and half” is often not good. Wireless systems tend to work best when you add more devices, and I sometimes see people say things like “I’m going to wire my house for lighting etc, and then put ZigBee battery sensors in” - this won’t work as the mains powered wireless devices provide the network for battery devices - no mains devices = a very poor network.