I think it has to do with the use case of being able to add a new search engine that isn’t in the list is in the realm of extremely obscure features, so it isn’t obvious that leaving it out is actually hurting consumers.

I’m not trying to be some kind of Apple apologist.

My point is simply that this is an obscure setting and there might be decent reason and more downsides to not add it, rather than some nefarious anti-consumer move.