‘actual’ is the key
Obviously married with children characters or homer/Bart Simpson have foibles built into the character characters can still be flat with foibles
But for character depth there has to be a degree of irrationality- like the rest of us humans
I acknowledged it was a well crafted/well written show- it just doesn’t have that extra dimension that puts it in the pantheon
and you clearly like the format- nothing wrong with that
People like Billy Joel more than Tom Waits , that’s fine too