I asked a senior Lackey at Spring Fling why there aren't any GIGAs or GPS Mazes in Europe published and she said that they have to earn the GIGA status back.
Also, there was a Czechia caching couple at the same event promoting their Mega in August near Brno and I posed the same question. They told me that the GIGA in Czechia is returning in 2025 because they aren't seeing the interest. Project 13 in Essen had a poor showing last year as well.
So, this tells me things are decreasing.