Web browsers are not document viewers. They are customer acquisition channels for massive tech ecosystems. They don’t serve users, but corporations. AI features, VPNs, crypto wallets, and countless of other nonsense.

Markdown, on the other hand, is a public good. It would empower writers to publish their words independently. It would strip out countless CMS systems, frameworks, trackers, and ads. All those things where the money sits. Markdown is practically anti-platform. It’s simple.

Source: Why web browsers don’t support Markdown

I get and support the argument that modern web browsers, especially the giants aren’t exactly the user-agent that we were all promised. However, the main reason why Markdown isn’t supported by web browsers is because there’s nothing standard about Markdown. Now, one can ask why doesn’t someone actually standardize markdown - and for that I will let you research about markup languages and why markdown isn’t a markup language and can never be.

Put another way, it’s not malice, but something far more systemic than that.

The good part about markdown is that you can employ your own markdown parser as a web app and the web is still great for it and all web-browsers will still allow you to do it.