If you look at Win XP, its EOL was in 2014. The major browsers only stopped supporting Win XP in 2017. So, Win 7 will still be usable until 2023 before the major software/programs stop supporting it. After 2023, you will need to replace Win 7.
I am forced to run Win 10 Ent LTSC 2016 un-updated in a virtual machine from my un-updated(since April 2016) Win 7 laptop because it is practically insane to run Win 10 Home or Pro or Ent, which comes with forced auto-updates/upgrades.
Since Win 95 days, I have not been infected by any malware/virus by adopting safe-browsing, have realtime AV protection, using a Limited/Standard user account for browsing and setting my home-router properly(eg WPS and Remote Management disabled).