Google is the dominant search engine essentially
everywhere except for China and Russia.
Amazon's marketplace dominance is pretty US/UK specific, and even there, there are plenty of alternatives. Amazon marketplace is actually only available natively in a small handful of countries.
I feel like most people in this thread are grossly overevaluating Amazon's ability to stay relevant. If a competitor pops up with consistently better prices/better products/better marketing then they'll steal users from Amazon and over time dominance is lost.
What exactly does Amazon have that prevents me from stopping the use of it?
Google has excellent quality search results and a ton of products with a huge lock-in to their account ecosystem. Apple has fantastic product quality. Meta has a ridiculous network effect in three of the four products I use it for -- I can't even leave two of them (Whatsapp and FB) despite not even liking them! And Netflix consistently produces and publishes some of my favourite shows.
Amazon has nothing I can't get elsewhere, it's just a bit more consolidated. With the exception of AWS, and as I said upthread, who knows if that will remain the same company.