Whoops, should have noticed your endorsement of syncthing before posting a comment mentioning this.
While Obsidian does save to individual files, the Markdown they use seems to be a superset of everyday Markdown. Eg, being able to use callouts (eg, Note, Warning, Info, etc) and embedded linking of notes.
The automatic backlinks are fantastic. And I've discovered that if I rename a note, all links to that note get updated as well. So no need to worry about orphaning pages.
I've added a handful of plugins as well. Off the top of my head, one is a dynamic table of contents (for that page), another helps to compose/edit Markdown tables.
You just described a friend of mine. He's a retired epidemiologist. Used to do tabletop modeling with his team, used to go to universities to give talks about what to do when an epidemic hits.
For context, he'd said back when Ebola was making headlines that "we're overdue for an epidemic, but this isn't likely going to be it". And then in February 2020 he warned me "it's coming, I hope you have a plan".
He had also shared the following. It was so striking, I had to write it down:
Rules for Understanding and Surviving an Epidemic:
I recently shared with him an article describing a confluence of data in the UK re COVID and the changing of the seasons, etc.
His response:
This is someone who needed to travel (by plane) later on in 2020, and was adamant he would be wearing a mask, adding that most people don't know how to wear a mask correctly.
Conversations with him over the years have been really informative. And yet it's made me realize just how hopelessly lacking I am in the training and experience to be able to grok the things he does. General medicine being one area. But also the likes of statistics, and things such as how/why it's not important to have 100% immunization, and how our brains aren't wired to easily understand what exponential growth means in practice. He's only too happy to reference studies; not just a specific one that supports his opinion, but looking up all the studies on the subject and working out whether they strongly support one position or a other, adding that if it's roughly 50/50, then the conclusion is there's no compelling evidence either way. This man loves poring over studies.
And to your point, he has made general comments indicating a lack of faith in humanity, not to mention some others in his profession.
Not for nothing, my wife and I got our annual flu shots last weekend.