Monopolies are bad, but is it a monopoly if they naturally gained market share because their product was first and better?

Honestly I’d be fine with them removing the “PMFN” clause, but I’d rather it be a law that it can’t be enforced because you know Valve isn’t the only one to include it. But even if they did get rid of it, I don’t think they’d see a major shift away from their platform.