Bivouacs/shelters are indeed quite popular, there are lots of permanent ones made of wood out here. Basically just a slanted roof. https://vindskyddskartan.se

Obviously rain is the big problem with not even having a tarp, and as tents are generally heavier than a tarp I'm not sure why that would count as the easy route.

Tents feel more like a house, you're sort of indoors. Plus it holds itself up, so easier to set up than a tarp, unless you just use the tarp as a blanket. I tried that, in the rain, not recommended at all.