The best de-brain rot vacation I had so far was on a remote island in Raja Ampat: it wasn't about the island being remote, but about spotty internet access. It was just the correct amount of spotty: enough for text to load and IMs to go through, but not enough for any serious photo or video content. I was able to get YouTube to download videos in 240p on one end of the island, but I had to be picky about what I select. After two weeks I felt like my old self again, but unfortunately, it popped like a bubble after just a few days.