Have you priced in the extremely limited freedom to operate they have? There is an extreme systemic risk to being a monopoly in a strategic position. It's an extreme beneficial position to be in, until it isn't.
ASML for now has a monopoly on cutting edge EUV. Since this is considered a strategic technology, the US dictates what they can sell to whom. This places ASML in a pincer. The US will develop a competitor as soon as they can if they can't get enough control over ASML, and at that point ASML would still be forbidden to sell to BRICS while losing the 'western' market as well.
So they're in a plushy seat, until the US decides they aren't.