A decade ago, I thought that maybe if reStructuredText had had a non-Python implementation (most significantly at the time, PHP and JavaScript) it would have conquered instead of Markdown, given how clearly superior it is.
Now, I’ve decided that the fact that reStructuredText wasn’t ported is actually bound up in the reason why it didn’t conquer: it’s too fancy, too complex. Markdown is an awful kludge that was built on regular expressions, duct tape and HTML and knows it’s unsound. It’s very strongly web-native. reStructuredText is beautiful elegance and perfection of form, but aggressively medium-neutral, painfully so when you only care about the web, and difficult to implement, and unforgiving of content errors.
So I still wish reStructuredText had won, but I can understand more clearly now why it didn’t, and in fact never really stood a chance.
I still sometimes wonder if reStructuredText had better acceptance outside of just the Python community if it might have had a better run for "default" versus Markdown's quirkier approach.
https://docutils.sourceforge.io/rst.html