What works for you doesn't work for everyone. For instance, family Spotify also doesn't work with multiple Echos like Amazon Music so you have to create separate Amazon accounts and link them to separate Spotify accounts so people in the household can listen independently of each other. But then with different accounts enabled on different Echo devices, it becomes impossible to control the smart home devices unless you switch to the owner's account, operate the device then switch back. Clearly this is not a great design. It's called a smart HOME, not a smart person! Smart devices should be accessible to all household accounts. Further, children's accounts should be able to be linked to Spotify accounts. Currently Amazon limits linkable accounts to two (adults only). It's these kind of limitations that detract from the experience and make it much less than optimal.
I suppose the answer in my case is to ditch Spotify for Amazon Unlimited but it just isn't as good and I'd prefer to have the choice.
I have found a simple solution. I have bought this set of three E-Family cloud plugs.
You set them up as per instructions. Then add them to Alexa. they work on all family settings and even have timers for when on holiday and countdown timer for kids tv’s etc.
they have much more features than Alexa
WiFi Smart Plug App Remote Control Socket Working with Alexa Google Home and IFTTT Support Timing Energy Saving Home Devices No Hub Required Control Your Devices from Anywhere (2 Packs) https://www.amazon.co.uk/dp/B07JN62N2M/