Why is using Sonos so hard?

Well, I plan on integrating access control and security into my network, but will be bringing in someone who can make sure the ubiquiti equipment is set up properly since this will be a critical service - unlike music - but, I will add getting the Sonos on fixed IPs and possibly it’s own Vlan as part of the project, and keep my fingers crossed - 

With UniFi (another user here) you either Ethernet wire every Sonos or use WiFi, never mix and match as you run into issues exactly as you are describing.

As for powering devices off, power down sensitive equipment likes computers / NAS and then just flip the breaker for at the fuse board a good 30 seconds., saved getting the ladder out. In my house (and probably yours) the electric socks are on spectate circuits so not everything in the house gets powered off.

I hate resetting clocks so I avoid the flip the breaker option. I added remote power switches to all hard to unplug Sonos, some simple switched extension cords, some pretty remote switches where the spouse can see them. Wireless ones are an option but more than I needed.

I love my Ubiquity gear but mixing the latest tech (from anyone) with the older Sonos firmware does take some adjusting.

Luckily the only mains powered clock here is on the oven, which is even better as its own its own circuit breaker. 
 

Saying that IKEA in the EU and UK have some cheap socket adapters which can be controlled by various Home Automation software and support Matter or using a remote control. At £6 a go they are an absolute bargain.

This is a good hint - I think I have 1 speaker wired, with the rest wireless. I’ll keep them all the same ( and set static IPs ) - 

The issue is if you wire one Sonos and don't disable the internal radio it creates an invisible 2.4 gHz network, Sonosnet, that causes other Sonos wireless speakers to ignore your wifi and try to connect to it instead.

Newer Sonos don't use Sonosnet which is a good thing.

 Maybe Sonos should add a way to set static IP Addresses for each Sonos device.  Sometimes reserved IP Addresses lose their reserved status.  I have had that issue on occasion with my ISP gateway ( modem/router ).

Static, set in the device, addresses can bring a lot more aggravation than DHCP which may be odd but usually works.

Setting an internal static IP is an issue too, when you have a screen and keyboard it is easy, without there is no good starting point.

I wonder (not enough to go digging again) how close to the current Linux release the Sonos firmware is. Some of the issues we are seeing might be fixed by Linux updates and we would see new (to us) features.

 Reserving in my ISP gateway does not involve typing in an IP Address.  It shows you the DHCP address the device has now so all you do is check that you want to reserve that address for the device.

 Sonos could do that in a similar fashion.  Show the IP Address the Sonos device has been assigned and allow that to be the static address.

Your gateway is showing you the dynamically selected IP address and letting you set a reservation, that is not a static IP address. Yes, it doesn't normally change but it is only reserved and is subject to the negotiation process in The RFC I linked above. A static address never changes and conflicts with other devices must be resolved at some level.

Yes, that manual reservation process sort of works once you have a DHCP assigned address as a starting point. 

Using a DHCP range IP address a for static assignment is not usually a good thing. Static assignments should be outside tne DHCP range to avoid conflicts.

Then with static IPs you get into the whole my network changed and my Sonos disappeared mess. Sure it could be done but does anyone at Sonos have the skill to do it, and does anyone have the money to pay for it.