Both Kaito and Shinichi lost a lot in their respective efforts to combat organized crime. They lost the ability to tell the truth, least others end up killed. They lost time, normal teen experiences, tackling a problem which adults ought to be handling themselves, and their innocence took a massive beating. They'd lost their ease-of-mind, paranoia sinking into every waking thought.
They'd gained a lot too. Friends, allies, knowledge, skills... But they couldn't say yet if it was worth it.
Even if they succeeded, would the outcome be worth the price paid?
Not that it mattered. They had no choice.