You don’t -need- it unless you are aiming to become public accountant to sign audited financial statements.

Most people want it because
1) it’s a designation you can put on your name card and resume to bolster your profile.
2) An entire generation of NUS/NTU/SMU seniors got the membership for much less effort because it used to be a 5 days course instead of all these papers. In the transitioning cohorts, we got no choice else cannot compete with our seniors when looking for jobs.
3) You can’t call yourself a professional without a membership in a professional body. Lawyers doctors engineers accountants all got professional body and to abide by a code of ethics and conduct.
4) It’s like a video game achievement, you chose this job, the natural progression is to unlock this title. Why else are you even playing this class for?

But ultimately the value and prestige of the title is dependent on the prestige of the industry as a whole. And if the whole accountancy major is reduced to BBCC then in my opinion it’s no longer the same as when it was AAA or AAB.