Market leaders have higher profits than the rest of the industry in general, because many factors allow them to do this. There's also sort of a rule that you can't have a higher price than the market leader because it offers higher value (gets a lot of benefits such as biggest 3rd party ecosystem, most known, most trusted, most experienced, etc), so the competitors have to price their products at a discount, and try to win customers on price, even when their product (in isolation) is "better" than that of the market leader. This leads to the market leader having the biggest profit.