No matter which country or region you're looking at, there are always some exceptions to the typical climate. Micro-habitats can be completely different from the accepted normal climate. There can be raging hot sandy desert for the most part, but also some cooler, humid woodland and grassland areas. Or it could be mostly rainforest, with some drier forest areas, but we still rate the region as rainforest because that's what most of it is. The geckos can live in these regions/countries but stay in the areas that suit them, the micro-climate that's way off the beaten track for the rest of the region.
Fat-tails do need more humidity, and do live in moist forests, but not rainforests. They also live in grasslands or along cliffs and rivers. As long as they get the right temperature and humdity, they can live on paper towels.... they don't care much as long as it's got what they need.
I like the planted vivarium, it's closer to what they've evolved to live in than the typical set-ups we see in the hobby. The plant would keep the humidity up without being too humid. I've tried the same thing over the years, but found the grasses were hard to keep alive. Some of the damage was due to crickets, mostly though, it was the geckos flattening it so often, the grass just gave up and died. Mind you, it also looked and worked pretty good with the dried grass.