It is a lifesaver, a few css commands and YT is usable.

One of the must haves if you take browsing seriously. My wikipedia.org customizing


.mw-body-content p {
text-align: justify;
hyphens: auto;
max-width: 70ch;
text-wrap: pretty;
}

Throws all kinds of errors for no reason, even with basic elements like #header.
It doesn't have any formatting aids either, though I suppose if all you care about is size that's not a dealbreaker.