I 'member the days of Win 98, Win ME and Win XP... made good money cleaning up malware - browser toolbars, dialers, god knows what - from computers. Some came from the hellholes that were Java, ActiveX or Flash, some came from browser drive-by exploits served from advertising networks, but others just came from computers that were attached directly to the Internet from their modems.
And I also 'member Windows being prone to crashes, particularly graphics drivers, until Windows 7 revamped the entire driver model.
Oh, and (unrelated) I also 'member websites you could use to root a fair amount of Android and Apple phones.
All of that is gone now, it has gotten so, so much better thanks to a variety of protection mechanisms.