Webapps and mobile apps really need two dark modes - the one you like, i.e. light grey text on dark grey background, and another one for AMOLED screens, that's actual light grey or white on pure black.
On AMOLED displays, that #000000 not only looks nice, it also saves battery, as it shuts the given pixel off. The difference is substantial - with modern UI trends that waste most of screen space, a "grey on pure black" color scheme can often keep more than 50% of the pixels off! Meanwhile, a typical "grey on grey" dark mode will keep 100% of them on.