
Bro, you are taking the whole point too shallow. It's not the fact that he quit his job that solves their problem, but the fact that now he has A LOTTA time to focus on his loved one, dedicating his time that he mostly spent on his job to Inwoo, accompany him daily from morning until night, making sure he ate at least twice a day, spending time with him, taking him out to get fresh air, making sure he was out of his loneliness by doing all of those together and staying by his side.
It was a showcase of his dedication to Inwoo to repent what he has done. It was definitely not easy to quit a job that you love (as he said he loves his job) but he did it anyway since he wanted to make up for what he has done to Inwoo.
So the solution to their problems was for Jiho to quit his job, really? ... (〜 ̄△ ̄)〜