Does it matter ? Yes, I mean in the old days, the shape of the bottom of your shirt (called “hem”, right?) determined whether or not your shirt should be tucked in.
If the shirt was a long-sleeved one, it came with a nice rounded hem, which must be tucked into the pants. For courtesy, modesty or formality, or all three, having an exposed rounded bottom was a frowned-upon “No-No”. But it was OK, if the shirt, especially a short-sleeve “hawaiian” type which always came with a straight bottom.
But times have changed. These days, we see our young men strutting smugly around town in shirts with exposed, untucked rounded hem (worse still, with a half-done tie, and shorts) going arm-in-arm with girlfriends dressed to the nines.
Tastes have changed too. Ironically, anything goes, just tuck it in.