See Markdown the way readers will
Markdown is easy to write and hard to proofread raw. A stray asterisk, a table row with one pipe too few, or a list that lost its indentation only shows up once the text is rendered. This viewer renders as you type, so the preview on the right is always what GitHub, a docs site, or a chat app will show.
It's also the quickest way to read a README or an AI answer that arrived as a raw .md file: open it, hit Fullscreen, and read it as a clean document instead of a wall of symbols.
When you need plain text instead
A preview keeps the formatting. If you need the words without any Markdown syntax, for example to paste into an email or a form, use Remove Markdown. To keep bold and italics in a LinkedIn post, the LinkedIn Formatter converts them to Unicode styles that survive pasting.