Unless you have a reliable WiFi network that is better then the provider modem/router/wap device, your signal reaches all the corners of your property and you only use the 2.4Ghz for IOT, I would not choose to use WiFi for home automation.
I started with WiFi because the devices were dirt cheap + you could flash them with tasmota.
Now I only use 1 power plug that is close to 1 of my AP’s and I went with zigbee for wireless devices.
Regarding your zigbee network: have a look at this if you have not done yet Guide for Zigbee interference avoidance and network range/coverage optimization
FYI: IKEA sells power adapters (TRÄDFRI) that also are zigbee repeaters and from what I read here these are a good solution.
As you see, there are some option for your traditional wall switches, that’s up to your preference.
I didn’t do anything about those since those places that have lights (all but 2) controlled by HA are automated.
To me, home automation is also about making the system smart to work for you so you don’t have to interact manually.
Still using wall switches is not really a smart home and you have to change your behavior to not use switches anymore.
But that’s my opinion, yours might differ.
If I’m somewhere else I tend to forget to switch off the lights since I’m used that this happens automatically.