Your comment is based on the premises that Meta/Google... are there to help you shop/find the best result once you've made your mind. For that purpose, an optimised search engine is indeed very useful.
But I don't think that's why intent profiling exists. What if, instead of helping you find quickly what you are looking for, they forced you through a less perfect system that, while leading you to your result, suggests you other, somewhat similar articles... Maybe you'll buy more? That incentivises ads and thus increases profits for the AdTech.
I was talking about Facebook's not so subtle nudge when they have already guessed your intent. It's already known that they do that. Then they show ads on their online properties few minutes later, people have already sensed this deception and their are reels made on this behaviour. How about facebook lets me search through the catalogue of websites who have opted to advertise with them. Maybe once it is well known that facebook also allows for normal search within their apps, other e-commerce website would be willing to pay a nominal fee to be included in search results.
But I don't think that's why intent profiling exists. What if, instead of helping you find quickly what you are looking for, they forced you through a less perfect system that, while leading you to your result, suggests you other, somewhat similar articles... Maybe you'll buy more? That incentivises ads and thus increases profits for the AdTech.