If Apple decides to make a search engine and eats $100 billion out of Google's $500 billion profit (made up numbers), Google will just spend back $100 billion (or whatever constitutes a blank warfare check) for year into completely annihilating Apple's presence. They will literally stop people from finding any page that even remotely mentions their 'AppleSearch' and also deprioritize a bunch of other products too unless if you type out, exact word, 'AppleSearch' or whatever it'd be called.
So now you're Apple, here's a question: Will you spend $200 billion fighting back? When will this stop? You're Apple, and this is a stupid move.
Both Apple and Google make less profits if they compete against each other, but consumers benefit from two search engines trying to compete against each other.
They will never make a search engine.
On the other hand, they have already made a search engine. Which you don’t think of as one, and which provides a boost to their ecosystem tie-in.
If you think they got it some other way, you weren’t using the Internet in the early 2000s