Don’t worry about curtain height in relation to cabinets, but make sure the curtain and its liner are at least 3” above the floor of the tub and the bathroom floor. Your spring rod make this an easy fix.
It appears you have a light over the tub, so the dark shower curtain does not create a dark cave. If no light, purchase a lighter shower curtain.

Hang the curtain at the ceiling. A white shower curtain to lighten up the room.

You don't have to use an "actual shower curtain" you could have a "curtain" with

plastic liner.

Fleming Guest Bath · More Info

With the daylight coming through, it looks strange. Can you get a dark liner?

IMO a glass shower screen is a much better solution in a tiny bathroom. I do not understand the reason for the cabinet height and certainly not how that affects where the shower curtain hangs.