According to this Website - still lots of people using Windows 7.
Desktop Windows Version Market Share Worldwide | StatCounter Global Stats
Especially when it comes to Steam's survey.
GoSquared as well.
Both sources really show that difficulty, since there is a steady trend up for 10 and down for 7 and 8, there's large spikes month to month.
It is possible with Steam, since the others go off of website hits, and if Steam stops working, as it did with Windows XP in 2019 due to Chrome dropping XP support, you can't access your games. The others go off website hits, and it's unlikely that if you're patching Windows 7 you'll be browsing the web at the same time, since like you said Windows 7 requires multiple reboot cycles.
Also, perhaps it's just coincidental timing, quite likely not, but Microsoft will issue a security update today to fix a gargantuan security issue, a large enough issue that the NSA is holding a conference about it. Will Windows 7 users get it who aren't on extended paid support? We shall see.
https://www.neowin.net/news/microsoft-expected-to-patch-a-serious-security-bug-affecting-all-windows-versions-today
NetMarketShare reflects much the same. Honestly it's not the apocalypse that Microsoft makes it out to be since really the largest threats are ransomware and malware, and really the only way to protect against them are to do your internet browsing in an isolated VM, or to use Linux. Second to those are security vulnerabilities in internet browsers and other software, and again those don't matter if you're using 7, 8, or 10 for the next few years.
https://www.wccftech.com/end-of-an-era-1-in-4-computers-are-still-running-windows-7/
