Every good hand-tool teacher says it. Pare the baselines clean. Go back with a sharp chisel before you glue. Most of the time it gets listed as a cosmetic step, or a fit thing, or something to do before assembly.
It is not a cosmetic step.
When you open a drawer, the joint gets racked. The front is pulled forward; the sides resist. That racking loads the joint at one specific place: the re-entrant corner where the baseline shoulder meets the tail wall. That corner is a notch cut into the wood. The notch's stress multiplier is called K_t.
A router-cut baseline leaves a 90-degree internal corner. K_t is around 8.
A hand-pared baseline, where the chisel bevel naturally rounds the corner slightly, brings K_t down to around 3.
The fatigue exponent for wood loaded in tension perpendicular to the grain is 14.7. That number matters. A 15% reduction in local stress at that corner multiplies fatigue life by roughly ten times. And the difference between K_t = 3 and K_t = 8 is not a ten-times improvement.
It is 1.85 million times.
That is not a typo.
At normal residential use, 20 drawer pulls a day, a cherry drawer box with a hand-pared baseline is beyond any fatigue calculation that matters. Not a hundred years. Not a thousand. The number has no practical ceiling.
A cherry drawer box with a router-cut baseline has an endurance limit of around 25N of pull force. That is the weight of roughly 2.5 kilograms. A drawer loaded with winter sweaters, pulled with effort, gets there easily. At 50N of pull force, the 50th-percentile service life of a router-cut cherry drawer box is around 5 years at 20 pulls per day.
Five years.
Old furniture survives not because old craftsmen were more careful. It is because hand tools naturally produce lower K_t corners. The chisel bevel rounds the re-entrant corner in the same motion that cleans the baseline flat. It was not a deliberate structural decision. It was a consequence of how the tool moves.
Modern router jigs produce exact geometry. The exactness is not the problem. The corner sharpness is.
Pare the baselines clean. Not because someone told you to. Because it moves the corner radius from inside your normal operating loads to well outside them. The 30-second chisel pass at the end of cutting the joint is the one that decides how long the joint lasts.