Two decades now actually. By 2016 we were already seeing the mass transition to browsing on phones instead of PCs, Windows 10 was already out and for reasons I am not quite sure of the old homepage and toolbar hijackers were on the decline and adblockers were on the rise although I am sure there were still people using malware ridden Internet Explorers for years after.

https://en.wikipedia.org/wiki/Browser_hijacking