Popup blockers were also a differentiator, once.
Just imagine if Netscape and MS made all their money from popups at the time.
But in the same way that an individual human might do something with a subconscious purpose and plausibly claim they weren't aware that's why they were doing the thing, so too can a organized group of people do something when it suits their collective purpose. The group drifts into a behavior which is advantageous, someone in upper management is pleased with it even though the drift wasn't steered, and encourages more of the same. As that process iterates, it becomes clear why they go in that direction all without some Senior VP telling everyone at a department-wide meeting to go in that direction.
The ad folks don't work around ubo lite now, because they understand it drives people to ubo actual.
Once that option is not really reasonable for anybody not highly technical... That's when the fun begins.
Makes switching easy.