Bit surprised no one mentioned using the LTSC releases of Windows. They're absolutely barebones (no clock/news/weather, media codecs need manual install) but apparently significantly faster and less bloated, and they boot faster too. The only catch is I'm not sure how you can get one unless you're fond of the deep seas.
I'm pretty sure you can use LTSC editions if you have the Microsoft Action Pack. You can definitely get the Enterprise edition (I use it, and there are no ads).
I forget how much it costs, something like $350/year from memory, but it's a no-brainer if you are developing for Windows, as you get access to loads of software, including Visual Studio, Office, something like 10x Windows desktop licenses and 5x server licenses, $100/m Azure credits etc.
I tried out the latest one and it was actually pretty crap. The telemetry settings were the same as regular windows (no off setting), the same crapware was installed like the Windows store, microsoft accounts, news applets etc...
I think the only thing it still has going for it is that it doesn't really change all the time. Oh and you can probably still install updates whenever you actually want to, because it's meant for production systems.
The old LTSB of Windows 7 was indeed a really nice, light and no-frills windows release but LTSC has become almost the same turd that Windows 10 has :(
