[bilbo0s]

I could be wrong, but I think Telegram's lawyers are advancing on the grounds of anti-trust, not necessarily anti-monopoly. Which, as you correctly point out, would require convincing a court that a company with a minority market share is a monopoly. (Apple doesn't even have a threatening minority. They have maybe 25% if that.)

In any case, I think they can make a convincing argument that Apple is operating as an illegal trust. (If you alter the historical definition of "Trust" a bit.) I think that's more what they are going for here.

Whether the court will buy it? We'll see? I certainly would not plan on a win if I were Telegram, but it's worth a shot.