- properties can “top up” their 99 year lease, if the developers/owners want to.
- at the end of the 99 year lease, the owners can sell to a third party developer if there is demand (they’d still have to move). this has happened before many times too. this is called an en bloc sale in singapore.
also, keep in mind singapore also has 999 year leases and “freehold” (effectively the “forever” style of property ownership common in the usa). freehold properties are both rarer and more expensive.
something like 80% of the land in singapore is on a 99 year lease.
personally i think it is a fantastic system.