There are A LOT of costs which are not explicit when owning a condo.
Honestly I have such low trust in the ability for humans to plan for the future over the now. It is like a bug in our psychology.
As a homeowner I have definitely had some 5 figure costs over the years that were totally unexpected and several in the low 5 figure range that really needed to be done. Doesn't mean I couldn't cover them in some way shape or form but they happened.
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.
hoas only make sense to me in condo situations - but even then you’re at the mercy of others
But in the US it usually implies neighbors above and below and on the sides.