This literally describes the older operating systems which don’t support modern browsers.
They’re unpatched, unsupported, and wide open to exploits.
Removing (implicit) support for 9 year old devices and 15 year old operating systems is not “chasing the bleeding edge”.
The older computers can use modern browsers just fine. It’s the operating systems that users are choosing to stay on that can’t. I suggest introducing them to Ubuntu or Mint. If all they need is a web browser, this would work great. If they need more, the basics are probably already there as well.
If that’s not an option, seems there is a project out there called supermium dedicated to maintaining a modern Chromium-based browser on older Windows systems.
Neither I nor CDCK explicitly endorse this supermium project; we have no idea if this will work, trash your computer, or send all of your computer’s data to the KGB. Of course, if you care about the data on your computer, you shouldn’t be running Windows 7 / 8.