Microsoft makes numerous millions from telemetry by improving their software products and then selling them for an increased value (no one would buy a buggy software product) - so how much more would a non-buggy software product be worth.
Microsoft has also closed its testing division which would probably be adding hundreds of millions of dollars to Microsoft's profits. This would have been impossible without the use of the telemetry.
The fact that Microsoft does use telemetry to make money has been lost because of the focus on selling the telemetry directly for money which at present doesn't happen.
The Windows 7 telemetry/spyware features were installed only if you let them be installed which many users did not.
Using a local account does nothing, absolutely nothing for stopping the telemetry/spyware operating on your computer. They know exactly who and where you are and don't need you to log on to a Microsoft account. They can read everything from your computer. The only way to stop this is not to allow your computer to communicate with the internet.
According to Microsoft management, there is no way to stop the 'telemetry' from leaving your computer. If this is true, this means there is a back door in the OS which no third party software can touch. It would be interesting to monitor all network traffic from a computer running these software products (it has to be monitored using another computer which has the traffic routed through it - and preferably not a Windows machine).