The EUV lasers ASML/TRUMPF builds don't even work the same way other "conventional" lasers would[1]. You physically can't get there by incrementally improving some existing process. Now I don't know how ZEISS makes mirrors that blown up to the size of a country would have imperfections smaller than a human hair, but I'm pretty sure it's no small feat either.
These companies invested decades and untold sums into this when few other companies even had incentive to attempt it themselves. Sure, other companies could eventually replace them, but you're not closing a 2-decade technology gap in an afternoon.
[1] It's a bit insane, really. Vaporizing falling droplets of tin with two laser pulses 100,000 times a second to get just the right wavelength? Here's a good video: https://www.youtube.com/watch?v=5Ge2RcvDlgw