This is how in brings better typography:

Fractions (frac) applies the diagonal (slashed) fraction style to numbers separated by a slash, as in 1/2 or 3/4. These are called fractions and are usually used in dimensions, recipes and mathematics.

The diagonal style is not the only way to represent fractions, but usually considered the most common one. They look natural, use space effectively and are easier to read.

Fonts that have this feature includes Roboto, Inter, Source Sans Pro and Lato. Try them with text like 1/2 1/4 3/4 and 123/45678.