[pragmatic]

Either is valid.

If you got your first taste of typescript from angular and have a full stack background in c#/ Java class based style will make you feel right at home.

React seems to oscillate between the 2 styles.

My recent work in Svelte send to favor functions and types.

IMO the biggest benefit of classes is the code organization it brings. Have you ever seen a “util” class or folder. That’s what tends to happen to a code base without strong cohesion. It becomes hard to find anything.

With typescript/js you have modules as a pretty good substitute.

What I love about typescript is that you can mix the two.

Mostly classless module based with the occasional class (logger with a constructor to pass in the current module name for example) seems to be what I like most now. Use what makes sense.