When font sizes are chosen by eye on each page, they slowly drift apart. One page uses 17px for body text, another uses 16px, and a third uses 18px for the same kind of paragraph. Each choice seemed fine at the time, but together they can make the site feel less put together.
Define a set of type tokens (named font sizes), like text-sm, text-base, text-xl and text-3xl, and pick from them everywhere. Headings, labels and body text then stay in one family of sizes. If you later decide body text should be a little larger, you can change text-base once, and every paragraph on the site updates with it.
If you want a different scale for headings and body copy, you can still build it from this core set of utility tokens. text-xl might translate to heading-md, for example. This keeps your entire type system consistent while still giving you easily readable semantic tokens.
