This is correct. Ossification of the application means greater technical debt but throwing it all away is bad unless either it is an internal application and you can spend time identifying related applications that operates beyond your documented APIs of the application or met the ire of your external customers (equals PR disaster).
The correct handling of this on a new project is to insist on fully documented public APIs so that you can rewrite that without too much worrying.
On existing ones, rewrite in parts with extensive internal testing (and if possible testing with your customers, but please do not use the modern Microsoft way of almost no internal testing) and full rollback plan in case it went disastrously wrong. Or just as this comment said, just create a new product and have a workable migration plan.
The correct handling of this on a new project is to insist on fully documented public APIs so that you can rewrite that without too much worrying.
On existing ones, rewrite in parts with extensive internal testing (and if possible testing with your customers, but please do not use the modern Microsoft way of almost no internal testing) and full rollback plan in case it went disastrously wrong. Or just as this comment said, just create a new product and have a workable migration plan.