At the top nodes and volumes, indeed there is no competition. They have a huge headstart handed to them basically by Japan screwing it up in the 90s and no one else being able to step (get it?) up quickly before the gap opened.
However, if they can't keep moving, competition that was trailing behind on larger nodes could get close enough that they become competitors for the high end. At first it would be slightly bigger nodes, but cheaper, which might be an acceptable tradeoff, as not everyone in the world is chasing performace over price. CPUs are so gruesomely overpowered these days that it may not really matter that much in many end applications.
Think AMD coming up behind Intel while Intel was thrashing around.
How long the AI hype continues may be important: if AI capabilities are needed in end-user equipment and that requires the real cutting edge processes, ASML/TSMC keep the advantage.
However, if they can't keep moving, competition that was trailing behind on larger nodes could get close enough that they become competitors for the high end. At first it would be slightly bigger nodes, but cheaper, which might be an acceptable tradeoff, as not everyone in the world is chasing performace over price. CPUs are so gruesomely overpowered these days that it may not really matter that much in many end applications.
Think AMD coming up behind Intel while Intel was thrashing around.
How long the AI hype continues may be important: if AI capabilities are needed in end-user equipment and that requires the real cutting edge processes, ASML/TSMC keep the advantage.