I will re-review the big three Singaporean mobile operators, Singtel, M1 & StarHub, in March 2023, making the reviews more in-depth and better than the 2020 version (I was pretty new to reviews then, lol), so I deleted the content on this page (but you can easily find the cringe reviews if you search a bit) and will rewrite it in April.
While I would love to review SIMBA (formerly TPG Mobile Singapore) as well, as tourists can easily get its SIM cards compared to the Singaporean MVNOs, you can only have up to three Singaporean prepaid SIM cards active on your name across all mobile operators.
So when I revisit Singapore, I will try out SIMBA (because it is cheap), but not this March.