Nothing keeps the condo owner from realizing how underfunded the association is and saving that amount each month for the inevitable emergency.

Most home owners don’t do this either, but it’s pretty much the same thing short of an association leaving stuff so long it ends up being more expensive overall.

Stuff like siding isn’t really all that hard to predict - it typically has a useful life and easy to calculate like a roof. Might get lucky or unlucky but it all averages out in the end over time. If you’re not saving/spending about 2% of your property value each year for maintenance you are almost always running on hopes and prayers.

Granted, the outlier cases a condo owner has far less control over the situation- including neglect to the point of building collapse.