Isn’t this kind of a hyperbolic comparison? This is revenue, and should be compared to total revenue, not profit. By this measure, if two people pay me $1, and I have $1 in costs, then both people are responsible for 100% of my $1 profits.
But the payment is pure profit because there’s no cost associated with setting Google as the default search engine.
Google doesn’t pay Apple out of thin air for no reason – it pays because of the popularity and market power of the platform, which only comes from significant, sustained investment by Apple. It’s not separable from the rest of the balance sheet. If Apple stopped investing in the platform, then Google eventually would too.