Parametrics saves time. No need to re-set up Accudraw / ACS everytime. Much easier to just mod the parameter.

OTOH, using Constraints to set up Parametrics can be a pain and bloats up the file. If you want to be able to move a Feature in one direction, you need to lock down all the other DOFs. A very time consuming exercise compare to Accudraw etc.

HUD dimensions would be a good way of providing the vast majority of parametric tasks which are really simple, avoiding the need for 'proper' Constraints.

Take this example of an arrangement of Hole features in a Slab. A lot easier to not to have all kinds of Constraints positioning the Holes. 99% of the time what is needed is just an offset and maybe rotation relative to an Edge or Face. Something HUD dims can already do for OBD.

The Features are already hosted to the Slab and can be transformed when the host Slab is rotated / moved, without the usual additional Constraints. Not 'proper' but what is needed 99% of the time.