But Safari is the default. And if all the options are equal, then there’s no reason to switch from the default. It’s hard enough to convince people to switch browsers in the best of cases, let alone when the list of potential advantages or differentiators you can offer is severely cut down.
iOS supports changing the default browser to something that’s not Safari.
It’s not only about the rendering engines; Brave on iOS has other features and a UI/UX that I like that’s not present in Safari.
3rd party browsers on iOS have other ways of differentiating themselves, especially if you use those browsers on other platforms, like bookmark syncing, etc.
90% of end-users couldn’t care less what’s being used to render their websites on iOS.