If every supermarket in the West half of the country is owned by one company, that is a monopoly even though they only have 50% of the market, as "the relevant

If every supermarket in the West half of the country is owned by one company, that is a monopoly even though they only have 50% of the market, as "the relevant market" gets analyzed to mean "the west side of the country". The real question is whether one believes that iPhone vs. Android counts as morally equivalent to West vs. East, due to how: 1) most normal people only have a single phone, and thereby they can't just randomly pop over to Android to buy something the same way they can just pop over to a different supermarket in a market with competing supermarkets; and 2) high switching costs--which are partly born from an active decision by these companies to make purchases be non-transferable--prevents people from even "moving to the other side of the country" (similar to the high switching costs of physically doing literally that) in order to switch markets.