Earlier quoted context omitted.
3rd party browsers are forced to use a webkit engine instead of their own. By any definition, this adds a severe limitation => crippled. I also think (I could be wrong) safari has access to a slightly different webkit engine than third party browsers.
A forced choice is only a severe limitation if it’s significantly worse. That’s currently a guess as there are no iOS comparable options to consider at this point in time. Further, Google has a competitive interest in eventually crippling their iOS rendering engine.Then again I don’t use desktop Crome so that could be my bias talking.
And this does not even begin to touch on Firefox.
The problem is a policy one, with Apple really liking their walled garden and veto rights to any design.