A great example of browser complexity moats holding back potential useful innovation.
If browsers were easier to make, someone could experiment with content negotiating for markdown and rendering it client side.
If browsers were easier to make, someone could experiment with content negotiating for markdown and rendering it client side.
The stuff you're talking about isn't about browsers its about the websites.
If you had a website that uses javascript to parse MD or any other markup, spit it out as trivial HTML with light DOM, client-side formatting can do everything you want.
The problem is that modern websites use patterns that workaround users' capability to customize the presentation of the website. They do not want you to look at their site the way you want.
I guess the best solution to that isn't browser-side .md rendering, though.