[1] https://www.theregister.com/2020/05/14/zerodium_ios_flaws/
Do you have a source for this statement, specifically in relation to browsers?
Let's consider Android. I wouldn't automatically assume that using Safari on iOS is more (or less) secure than using Chrome or Firefox on Android - they are all provided by well known tech companies with years of expertise building browsers and a focus on security.
Controlling the execution environment is part of iOS’s defense in depth strategy. Focussing on browsers alone is a red herring. You have to look at the whole system.
It’s true that Google or Mozilla may be able to produce an equivalent level of security in a browser engine, but that’s a false comparison, since alternative browsers are not limited to just these companies.
You can also verify that the world is run by lizard people by googling.
They don’t. All of those platforms are less secure than iOS.