I'm also on 1440p and seeing your website with that "huge" font made my instantly happy.

My Firefox is scaled up using layout.css.devPixelsPerPx with a value of 1.2 and even then I've to scale up most websites to at least 120% in order to see anything.

Everything is mobile first these days

We had to write a line of business app used by office staff opening mail to feed high speed scanners to support mobile first with a responsive design.

As a web developer in the past I found - though maybe that has changed in recent years, let me know if that is the case - there aren't any real resolution-independent units you can use to design an interface that is comfortable on every medium. You can peg your design to things like viewport width or font size, but you always end up having to make an arbitrary decision at some point, because there is no way for the web browser to know the physical dimensions of the screen the webpage is actually being displayed on. You have to make educated guesses based on the relationship between width and height, user agent and other headers, stuff like that, and create different stylesheets for each case. The style for the 1920x1080 screen (rotated horizontally) of the smallest smartphones can't have the same font size as the style of a 1920x1080 30 inch desktop monitor.

Hey man, I work in email dev, I'm at least a decade behind current web dev standards.

You are incorrect. All CSS units are defined in a resolution-dependent way. (I think there has only every been one exception to this, an experimental unit `mozmm`, now discontinued, that attempted to be resolution-independent, representing one physical millimetre.) On screen, the px unit is king, being defined however the device chooses to define it—most commonly one or two device pixels. All other units are defined in terms of it: 1in = 96px = 72pt, &c. On print, the ratios are the same, but physical length units actually have meaning now, corresponding to physical measurements—well, maybe they do; in practice browsers play fast and loose with it all, second-guessing the website’s stylesheets all over the place, which is normally a good thing for users because few websites take care for print stylesheets, but is utterly debilitating if you actually care and want precision.

Now the question of what the root font-size is (a unit I like to call “browser em” or “bem”—I’ve never heard anyone else give it a proper name)—that’s a much more interesting question. It’s almost always 16px (I have no stats ready to hand, but I’d suggest >99% of page views), but there are devices out there that have other values, mostly between 13px and 19px, and you can change the value in some browsers also. However, website layouts commonly break if the value is not 16px, if the font sizes are based in bems and media queries in px, or font sizes in px and media queries in bems, and the developers have assumed 16px (which is completely normal). The ideal situation is to use either px everywhere or bem everywhere.

In theory, using relative units everywhere is potentially nicer. In practice, you’re fine using pixel units everywhere.

But 24px is still way too big.