What's keeping the SSB low now is actually a strong SGD.
It's actually about expectations of
future SGD exchange rates to be precise. And SSBs specifically aren't internationally available and are keyed to the 10 year Singapore Government Securities rate, so they're a little different than some other interest rates.
....But even that's not clear. It's possible to have global market expectations of a "flat" or "weak" Singapore dollar while also having lower interest rates. That can happen if there are compensating supply and demand factors. For example, if Singapore dollar denominated savings vehicles can command a premium due to their perceived expected safety over longer terms. Or if market participants (mostly domestic) are satisfied with lower interest rates because they have fewer alternatives and/or are more risk averse. (Yes, this seems to be true to some extent. I really can't fully explain Singapore's mortgage rates in relation to high quality savings vehicles.) Or tax-related reasons. (I generally have to pay U.S. income tax on bond and bank account interest. U.S. municipal bonds are a notable exception.) Or some combination.
The other factors you describe may be true prior to the recent events, but hints of deglobalisation is happening, and the move to chesper country would slow and that could put SG at risk, but not for the reasons you describe. To the extent possible, likely more onshoring for foreign companies back to their headquarters.
I think we can be more specific: "de-China-fication" is what we're really talking about, right? COVID, Hong Kong, Taiwan, and to some extent Russia's invasion of Ukraine have shaken confidence in China's reliability within global supply chains. Global multinational companies are now walking briskly (but not running), I'd say, to diversify their supply chains. They want at least emergency backup options in countries such as Vietnam, India, Malaysia, and a few others just in case the Chinese government does something unwise.
I'm not currently predicting that China will decouple/be decoupled from the global economy. However, businesses are definitely making contingency plans.
I'm not exactly sure how Singapore will do if there's a China decoupling event (in that unlikely event), but I think Singapore would be at least relatively OK. Singapore happens to be the current and primary beneficiary of China's abandonment of the "One Country, Two Systems" policy with respect to Hong Kong. And to be clear nobody in Singapore as far as I know is wishing anything except the best for Hong Kong and Hong Kongers.
