People hate change, and absent a catalyzing event or order of magnitude advantage, it will take a decade for usage patterns to shift.
E.g. Kagi over Google
Kagi could hypothetically be 25% superior in all searches.
Most people don't know and don't care. Search is the thing that pops up and they type into. You can even change that? To what? There are others?
Firefox had tabs.
Chrome had faster javascript. (Although moreso substantial free marketing on highly-visited webpages)
That's the sort of thing it actually takes to shift users.