Just spend 20 minutes learning LaTeX. If you’re already not doing anything more complicated than what you can do with markdown, that’s all the longer it will take.
Even going with bare TeX is surprisingly nicer for plaintext files than I would have imagined. Yes, figures can be hard. But not really much harder than they are in any other tool. With the bonus that I have never really seen a document regress with the addition of new sections.
Really the hardest part of figures and such is coming up with the actual figure in the first place. Most layout issues are ultimately solved by editing the figure.
If you learned it in 20 minutes please point me to the tutorial.
If this is actually a point about latex being difficult to (say) write libraries for then I agree profusely but equally if you are writing latex-without-latex or whatever then you still have to deal with latex's wackiness even if it's got a shiny new frontend with its own quirks.
Some billionaire funding a well designed latex killer would probably be a real gift to science - there is probably a lot of ground to be made up in spreading information (i.e. rendering latex for the web is surprisingly hard) and adding features like (say) structured programming to things like writing mathematics in LaTeX - I'd love for my work to be checked by a CAS automatically for example.
As a personal aside, I can't stand the LaTeX syntax; needing to have a \begin{itemize}, \end{itemize}, \item for every list, as opposed to a simple dash uses way more characters, adds more visual noise, and makes it less pleasant to read when editing. Ditto for something like \begin{tabular} as opposed to a pleasant ascii grid.
Write in a plain text editor, have evince open the generated document, it will reload when updated. Then use inotifywatch to generate on save, or just write a hook in your text editor that will update the pdf.
You don't need to use overleaf to get the overleaf experience...
Ah, the Dropbox comment springs to mind: https://news.ycombinator.com/item?id=9224
Adding a hook for compilation in most decent editors is only a few lines of config, and many popular editors (GNU Emacs, vim, m$ vscode) nowadays have packages that have these hooks predefined, so it pretty much just comes down to installing a package, which I hope you don't think is beyond the capabilities of the average user. Alternatively there are editors like texworks which provide exactly this feature out of the box.