6-12 months is a good starting point particularly if you have dependents. Some investments such as Singapore Savings Bonds can be counted as semi-liquid, since your principal is guaranteed and you can redeem anytime with a month's lag.
I wonder if experiencing 2020 made some people rethink this, as previously unthinkable things happened like the closure of bars, clubs, cinemas etc for months, stoppage of construction work etc. The airport and aviation sector may be in doldrums for years.
Maybe most of us here are fortunate enough that our jobs and income carried on without interruption, but it's also this group that tends to have less problems saving. It's those who earn less that have to spend most or all of what they earn - even putting aside a few months' expenses is going to be tough.