Forgive the long post, but this is the sort of question that will get 50 different answers. Here's mine, and I'll attempt to answer your question from the other thread too. Personal tastes/preferences are often part of anyone's home networking setup. Maybe there's some info here that would be helpful to someone though.
IMHO Putting all APs on wired backhauls, when configured correctly, frees up more spectrum for WiFi clients. This is because you're no longer using part of your available spectrum for the wireless backhaul. Benefits: Reliability, and improved WiFi client capacity and speed. Note that most mesh networks use part of the 5GHz spectrum for wireless backhauls.
My philosophy is "Ethernet wherever possible" so I have ethernet pulled to entertainment hubs and all my APs. My needs are simple so I use inexpensive home-network quality switches (I'm personally fond of the LinkSys 8 port SE3008 units) with gigabit ports and place those on UPSs at the end of each ethernet run. I plug the APs into the switches along with any other ethernet devices nearby (AppleTVs, game consoles etc) and run all of them back to a main switch near the home router and modems (I have dual WAN failover internet).
It's my understanding that Hue's Zigbee protocol plays exclusively inside the 2.4GHz spectrum. Under certain circumstances, 2.4GHz WiFi can cause interference, making the Hue bulbs slow or lazy. I have a couple of Hue bridges. Like WiFi APs, "more" doesn't always mean "better" - I feel the fewer APs and bridges you have to run, the fewer collisions and interference you'll deal with and the simpler your network becomes when it's time to troubleshoot something.
I have a single AP in the house dedicated to 2.4GHz, and the rest are dedicated to 5GHz. I have about 30 devices on the 2.4GHz WiFi, but they're all outlets and other lightweight IOT objects. None of them place any kind of demand on the network, and they all stay connected. I then set my Zigbee channels on the Hue to be at opposite ends. So my single 2.4GHz WiFi is on channel 6, and my Hue bridges run on Zigbee 11 and 25, with great results. I have a bridge in the basement, and one on the top floor. Coverage in the middle is perfect.
See the second graphic on
this page
With the exception of the long-ish list of IOT devices only capable of 2.4GHz, just about everything else at home is 5GHz capable (all the HomePods, iPhones, iPads, Logi Doorbell etc) so I run a couple of 5GHz APs, at the full 80MHz*, and those comfortably support everything else. Same SSID and password across all WiFi though, in case one of my 5GHz clients struggles and needs to drop back to 2.4GHz for a bit.
*
Channel bonding means your 5GHz network crosses multiple channels, giving you faster throughput but fewer non-overlapping channels to work with. I have one 5GHz AP using channels 36-48 and the other using 149-161, giving me two clean 80MHz pipes with no overlap, and none of that valuable spectrum being wasted on backhaul.
