If all you did was an entry level "bar exam, it'd be pretty much useless. A newly graduated CompSci student, is really just an apprentice, who may then (if they continue to work hard, and are given challenging work) go on to become a master craftsman/journeyman over the next 5/10/20 years.
The same is true of those other fields too really - I certainly wouldn't want a newly qualified doctor operating on me, or lawyer defending me, or civil engineer designing a bridge I'm driving over. It's nice to know that someone has been professionally educated and passed some entry level exam, but to be useful in a field it's experience that counts.
Doctors go through residency after passing their exams, we should have the same for engineers. Civil engineers have layers of seniority and designs of junior engineers have to be reviewed and approved by senior engineers, we should have the same.
The same is true of those other fields too really - I certainly wouldn't want a newly qualified doctor operating on me, or lawyer defending me, or civil engineer designing a bridge I'm driving over. It's nice to know that someone has been professionally educated and passed some entry level exam, but to be useful in a field it's experience that counts.