It is a cute shirt and we could easily make it a reality:
It’s been done: en.wikipedia.org/wiki/Whisper_(app)
And more generally, anonymous message boards have been around for a very long time. I don’t really see what niche is left to fill. It’s also a huge risk to build a product around anonymity and controversial opinions. People will use it for illegal shit and you have to deal with that. At least 4chan has a small army of janitors to keep the site clean and posting controversial opinions isn’t even its entire identity.
Does it count as biohacking if you’re trepanning your own forehead with a dentist drill? It won’t let you sense magnetic fields, but it might allow ghosts to tickle your prefrontal cortex?
By the way, if anyone can find Heartbeat in the Brain, please let me know.
I liked the sailing portions in Wind Waker, they’re pretty chill. My bigger problem with that game was the number of mcguffins you have to collect. Even if the ship was going lightspeed, most of the game is looking at your map where the next key/treasure/artifact is marked, sailing there, fighting one enemy, repeat. Even after all of the map was explored, it kept going. Member that tiny island you found first thing? Turns out there’s not one, not two, but three magic artifacts buried in the sand! Now go fetch, boy.
The only thing that kept me sane was the sound of rolling waves and gently swelling music

To get a similar experience in the exact opposite way: travel in a big group. In a group of 30 there’s usually someone who wants to join, and even if not, you don’t have to feel bad about breaking off and doing your own thing for a bit, because no one expects you to do everything together.
You still have the basic structure of the trip to get everyone together for a travel day and discuss your adventures during a long bus ride, so I think it’s really the best of both worlds.