A monopoly simply has to have significant influence on supply of a good. In the UK that can be as low as a 30% market share. Qualify a market enough and any company can be a monopoly (I'm sure there's some geography where Lyft or good ol taxis represent a monopoly), so it's important to determine the size and importance of a market (a monopoly over food in a small town is still problematic). So while I cannot say these companies are monopolies--we have the Department of Justice for that--many companies on your list would make a compelling case, were they to abuse their market power.