But in the real actual world that we all actually live in, such a company would quickly get snatched up and bought by the competitor before the general release of the drug or a captured government agency would get lobbied to put controls on who can produce and distribute the drug.

Monopolies don't sit idly by when disrupters come to town, they buy or kill them.

The competition model assumes business people act like victorians who play by the rules to be sporty. It almost never works like that. Dirty tricks and shenanigans are widely deployed.