About that age 62 (or 63 nowadays) earliest qualified SRS withdrawal age… ”Classic” retirement age is 65, and many people work past 65. I wouldn’t assume the earliest SRS age will end up happening. Also, usually you won’t start withdrawing until the year after you stop working. For example, if you retire at age 63 on July 1, and your birthday is on September 15, you won’t start withdrawing until the following January when you’re 64. That’s to get your taxable income (or most of it anyway) behind you so that you’re in a lower tax bracket (typically zero).
On top of all that, you won’t necessarily cash in your SRS investments for immediate spending. You might keep some or all of the proceeds invested. And if you end up retiring outside Singapore an SRS account might not end up working as well as you thought from a tax point of view. (Although it’s still a “reasonable bet” in most cases.)
I agree that’s a very strange thing to do in most cases. SSBs are limited to $200,000 per person (except if inherited), so if you’re stuffing lots of cash in low yielding but liquid SSBs why are you “burning” any of your $200,000 quota within an account that you can’t withdraw from (without a penalty) until at least age 62 or 63? For foreigners and late career individuals SSBs might make a little more sense, but it’s a strange choice generally. Of all the accounts you have, or could have, SRS accounts are inherently long term. Pick something(s) long term!
Another issue with SSBs is that they pay interest, interest you can’t actually withdraw from an SRS account (without penalty) before age 62 or 63. And nobody seems to offer automatic or automated SSB interest reinvesting. So you’ve got some labor effort involved to monitor that interest and reinvest it. If you can reasonably avoid that labor effort, why not? (And they mature in 10 years, so you’ve got to monitor that too. And that might happen in a lower interest rate environment. Yuck!)