I use TiddlyWiki via TiddlyPWA. It's an offline-capable PWA with builtin sync and encryption. It doesn't have folders but it does have nestable tags. I don't think it supports markdown out of the box, but I'm positive you can find a plugin to use markdown. Plugins are crazy easy to install in TiddlyWiki; you just drag and drop the plugin into your wiki window and confirm the installation.

I'm sure there are special cases where residents would need bathroom access directly from their apartment, but are there any good reasons for private bathrooms, other than convenience?

To me, one of the most interesting things about converting non-residential building to residential is the potential for different ways of living. A shared bathroom and kitchen with offices surrounding a communal area could lead to a more communal lifestyle for residents.

Yes I read that and explained why I don't think its relevant. Facebook can't slow down progress on the fediverse because:

1. progress is already slow. The fediverse has been in development for 15 years and still is a clunky, niche network and likely will always be less polished than large corporate networks.
2. Every developer on the fediverse is aware of the EEE playbook and next to none of them will try to remain compatible with any corporate extensions.

The numbers for lemmy are probably way outdated. Take a look at https://lemmyverse.net/communities. It lists 636 instances but FediDB only has 302. And remember most of this growth has only come in the past week or two.

Also, mastodon only has 1.25 million active users according to FediDB, though that's probably outdated too.