Because this is a Gish Gallop of weak individual reasons batched together to make it seem like a stronger obvious argument when it’s not.
> How can Google own the entire ads market and still be allowed to compete in it?
They don’t. Amazon and Facebook both make a fortune from ads. You need to be more specific.
> How can Amazon be allowed to sell competing products in their own marketplace, when they own the actual marketplace?
Go to a store, this is what Walmart, Albertsons/Safeway, Costco, etc have been doing for longer than any of the FAANGs have existed.
> How is Apple allowed to disallow any other web browsers on their mobile devices? We already went through this with Microsoft in the past but suddenly it's different?
The same reason you can’t put software you want on a Xbox/PlayStation/Switch.
> Why is Google allowed to rank their own products in front of more general results?
Because it’s their algorithm to do with what they want. If they want to erode public trust by using it to advertise their products, that’s their choice. Other things they adjust the algorithm to do: filter malware, filter porn (by default), filter unreliable sites, etc. You’re going to have a really hard time defining what’s “fair” for a black box algorithm to do.