It makes sense how certain threats that were once daunting when you start become trivial as you progress. If everything from the easier biomes scaled to you, then the game would be ridiculously challenging for no particular reason. If you get one shot in a biome that you are unprepared for, that's by design. I haven't died very much on my first endgame world, but every time I did it taught me how to carefully approach each biome and to be extra prepared for the nuances of said biome. The swamps still kick my ass even with maxed gear if I'm caught out at night.