i agree that policy work is almost always non-transferable. If you want transferable skillsets, go for corp services jobs such as Finance, or for market development jobs (SPRING,
EDB etc). If you already have a specific industry in mind, you can join their regulators (e.g
MAS, if you are thinking of transferring to the private sector (financial industry) as compliance officers in the future. (but why not just go private sector in the first place?) Statuatory boards are closer to industries, and as such, would usually have more transferable skillsets than the civil service.
"They spend most of their time in office reading newspaper, generating weekly briefs for the team. In school i felt really fun to analyse governmental policies and their exact impacts. I envisioned doing this kind of job." On your extracted quote, i'm not sure if you know what a policy job is like. Since you are an undergrad, take the opportunity to do more internships (both public and private sectors), and experience both sides. You'll need it to bolster your resume anyway. However, public service internships usually give interns research projects to do, which is very different from the day to day work. Anyway, what you describe seems to be more of a research type of job, rather than policy. Research jobs usually have looser timelines.
Anyway, my personal experience is that civil service only pay lip service to work-life balance. Our hours are approximately 9-11, and sometimes including weekends. Of course, it is highly dependent on your area of work and bosses. Others might find it different.