It would start at 90%, but drop for reasons the other reply said
Also: no longer would it be advertised as a browser to everyone who visits the Google search page. No longer will a conglomerate of what should be like 20 different companies in 14 different sectors be able to easily manipulate every website into optimizing for their products, so the average user will feel far less inclined to stay with them if there’s an alternative that works better for them