In New York, some homeowner pay over 1k a year tax for the right to have stairs leading into their units. in essence, because the stairs encroach on city property, they can be demolished at any time leaving the owners with no access to their properties.
Looks like the buyers didn’t read their contract.
California has Mello Roose property tax, you need to pay whether your have stairs on city land or not.
California is much worse than NY