It's not my favorite feature by any means but linebreaks are almost always an issue: practically all Markdown-ish or wikitext-ish formats don't give significanc

It's not my favorite feature by any means but linebreaks are almost always an issue: practically all Markdown-ish or wikitext-ish formats don't give significance to single line breaks to allow hard-wrapping the source without affecting its rendering, which doesn't leave you with many "nice" options for actually doing explicit linebreaks when you do want them. I've seen ones where you put something like a plus at the end of the line, the spaces from Markdown, or something like MediaWiki's format where you just can't do it without falling back to writing in some explicit HTML.