On emissive / colour displays, this still is my preference:

https://codepen.io/dredmorbius/full/KpMqqB

On e-ink, the off-white / off-black colour palette is actually something of a probem, though the page otherwise remains highly readable.

From the original page, the lack of margins is a problem. Text running straight into the gutter is a readability problem.

I think that is very good (even though they say it is satire, it is good). (The end user should apply their own CSS if wanted; my idea of "meta-CSS" (not implemented or even properly defined yet) would allow the end user to conditionally apply CSS, so that for example it will only apply to those that don't have their own CSS (or whatever other criteria you might want); meta-CSS would also be the way for the user to configure media queries such as dark mode preference, etc.)

For some web pages, deleting the CSS can help, sometimes not. Perhaps the way to go about such a thing is to consider mainly HTML, also considering CSS and ARIA to fix the layout (some web pages have forms that don't work correctly when CSS is disabled, but I have seen them have ARIA; an implementation could use ARIA to fix up any forms that are broken by doing so). So, while the CSS can be deleted, it still might need to consider it for some purposes, such as checking if something should be removed or formatted differently (e.g. emphasis, fixpitch, etc; HTML can specify such things too but it is not always done properly).

(That web page does have Google Analytics, with the comment "yes, I know...wanna fight about it?" preceding it, but you can just disable JavaScripts to avoid it.)