Because Windows 10 is very chatty to the mothership.
I frigging hate this. Start playing online next some process/service is saturating your network and it night impossible to find the culprit when all it reports is svchost.exe for example.
https://en.wikipedia.org/wiki/Svchost.exe#Identification_and_management_of_hosted_services
None of the above methods allows the user to identify which of the multiple services running inside a svchost instance taxes a particular resource, e.g. processor, disk, network or memory; the Windows Resource Monitor only does accounting for most of those resources at process granularity. It does however account for processor usage at service granularity by going to the "CPU" tab.[10] A service-aware list of TCP connections and UDP ports opened can be obtained using netstat -b.
In linux at least I can easily identify what's using the network and stop the service. Then again I probably only have like 5 services running (ntp, dhcp, dns, ssl etc)
It also restart my machine with upgrades and wake it up when it feels it needs to upgrade. I lost a couple of hours in powercfg already trying to fix this issues.
This use to drive me insane but there is fortunately a fix for this (not for Home edition though I think) where you can set it to only notify you of updates like in past versions and then you manually select the download/install option. Glad I sorted that schite out.