Plank Units represent physical constants, they are there to make equations and more importantly hypotheses/predictions continue to work in a world where measure

Plank Units represent physical constants, they are there to make equations and more importantly hypotheses/predictions continue to work in a world where measurements can be constantly refined. Hence they their actual SI values have quite a bit over the years. This is also why Plank units aren’t used much outside of theoretical physics and cosmology which are fields where using absolute value based on current measurements won’t mean that much.