到家 as an adjective (perfect/thorough) is different from the literal 到家 (to arrive home). Context makes it clear: 我到家了 (I'm home) vs 功夫到家 (skill is top-notch).
usage
Often used with 不 in the negative: 不到家 means not up to standard, lacking. Common pattern: [skill/quality] + 不到家.
