Why is professional advice, such as from lawyers, often expensive?

Well, I'd say the main reason is that professional expertise takes years to develop, so clients are really paying for that accumulated knowledge. Like in my work as a UI designer, when I first started, my designs were quite basic, but after several projects and continuous learning, I can now charge more because my work delivers better results. The same applies to lawyers - their advice comes from years of study and real case experience. For example, when my friend in Shanghai needed legal help with a rental dispute, the lawyer's advice solved the issue quickly because they'd handled similar cases before. That deep understanding is what makes their time valuable.