Windows 10 could work out decent if you manage to get ahold of a license for the Enterprise LTSB/LTSC edition, which comes with much less bloat by default. You could then get someone in the know to further trim it for you from all the remaining garbage. Or perhaps, if you consider yourself an advanced user and have the time to figure it all out, you could even do it yourself by following the list at https://docs.microsoft.com/en-us/win...osoft-services as a start (note: this is is nowhere near the full extent of what should be done). If done right, you could end up with a decent system (also because earlier Windows versions were not that great to begin with either).

However this is most likely out of reach for the average user, and thus I'd suggest staying with whatever works out for you at the moment, no matter if it is being updated or not. Security in Windows is illusory anyway.