They can be. I bought a Galaxy s22 with a broken screen for $150, and my carrier just gave me an $1100 credit for it on a new iphone. I don't need an iPhone, and I will be selling it to get yet another cheap phone and pocketing the money, but it goes to show just how much phones do not cost to the people producing them
The Android licence is free and the Play Store infrastructure has to support tens of millions of devices.
I'm not saying this is an acceptable level, but Samsung ain't putting a dollar toward Google running the store, in fact, they'd much prefer to run and maintain their own.
That's not true. Phone manufacturers need to pay if they want to include Google Play in their devices, it's not free. It can cost as much as $40 per device.
I don't think ads showing something related to what I'm looking for are bad in and if themselves. I want to find related content, the problem is that these are often not in any way related to what I'm looking for. It's just a list of who paid to be listed there.