It occurs to me that this is like supermarkets charging companies to put products on their shelves, then also launching their own brands and competing with them

It occurs to me that this is like supermarkets charging companies to put products on their shelves, then also launching their own brands and competing with them on their own shelves. I think it's easy to see how customers are harmed by this, their choice becomes the supermarket brand or whoever shelled out the most for shelf space. So Google search is an android home brand? (Also why isn't the supermarket thing deemed anti-competitive?)