Comment by BartjeD
The USA is a hostile environment to visit, for Europeans. It's a theme all over western and northern Europe to avoid it.
If you were expecting European attendance, that would explain why it's different from the past.
It's the same in science circles, tourism and even business travel.
I completely agree with you, but this event was held in October, 2024--Trump's horrendous behavior wasn't an effect on that. There are other reasons folks internationally probably don't want to travel to Texas aside from Trump--but in this specific case I think it might have more to do with the fact that LPMNR is a traditionally European conference randomly held in the US.