Why is everything so tiny?

What resolution is your display? Is it HiDPI?

Your profile doesn’t indicate your operating system. Some Linux Desktop environments have controls to manage HiDPI displays but I don’t know if those controls go down to individual application level. I don’t think that Audacity has a scaling setting to allow use on such displays so,at best, you might have to change the display resolution for Audacity.

ATB,
Neil