That's true! SSBs are outperforming ordinary Singapore dollar bank deposits, fixed deposits, and cash in a can. SSBs are slightly less liquid, though (maximum 5 weeks to withdraw). If the reduction in liquidity is acceptable then SSBs can be comparatively attractive.
No, SSBs are only nominally guaranteed by the Government of Singapore. You (the SSB holder) assume ALL omnipresent inflation risk, and future inflation over your holding period will determine the real outcome. You could come out ahead, even, or behind — even well behind. All those outcomes are entirely possible with SSBs.
Likewise, the past Singapore dollar inflation rate is not necessarily indicative of future results. Nobody is offering any real outcome guarantees here, sorry to say. SSBs (beyond reasonable Paragraph #1 holding amounts) are wagers in favor of low Singapore dollar inflation (i.e. wagers against moderate or high Singapore dollar inflation).
By the way, we should get another month of inflation data from Singstat before the next SSB's purchase deadline. We should also get the next SP Services quarterly electricity rate tomorrow (July 1), and we already know there's some more Singapore dollar inflation baked in with the successive GST hikes for the next 2 years. So we'll get a few more clues about inflation going forward, but it's still an uncertain wager.
A 5.4% inflation rate is not "anal" or miniscule. It's basically the whole ball game, actually. Reality is reality.