The people who know what UBO or a firefox even is is the vast minority. Google could single handedly completely fuck over the free internet and a majority still wouldn't give a fuck as long as they get that sweet sweet one click convinence. The average consumer who plays on their phone and tappy taps on their laptop have zero clue how their devices actually work, or that there are more privacy friendly options. They just want their shit to work, privacy and daddy google violating their basic human rights be damned.

Oh and also some websites make it a huge pain in the ass if you aren't using chromium. I think its a bit of a conspiracy but could be wrong.

Also stop shilling firefox and start shilling Librewolf