i agree with that too for room temp non-frozen cakes.
however i shave the sides of and ice frozen cake tiers
but i've never seen the video in question -- don't know how he does it
i'm just encouraging op to try this at some point for these various reasons
sometimes for a 13x10x7x4 cake order i will bake off a 14x11x8x5
then there's that almost 1/2 inch shrinkage from baking
a 10 inch comes out of the pan about 9.5 inches give or take
(for non-pound cake recipes, for example sylvia weinstock yellow cake, wasc or any white cake)
then i have my shaving fest (after assenbling layers into tiers and freezing)
and then i have a true footprint on the cake itself (not the icing) of my target measurements
also this way i can layer my buttercream icing on very efficiently no thick or thin areas all the same 'width" if you will
i use surprisingly less icing
i like doing this a lot
it's a finer point, a subtle thing--the trimming i mean-- but an important one that i encourage the op to at least explore
i should prolly bake in sheet pans & cut out all my tiers but...