[alkonaut]

The truth I think is more often that the legacy system is too old and brittle to improve, and customers are demanding ever more complicated features from it.

So you rebuild as a new system as a gamble, because even though it shows all the traits described, the new system is at least one that anyone is willing to develop, and one where features can be added, and to which people can be recruited.

We know big rebuilds have small chances of sucess. But that doesn’t mean you shouldn’t do big rewrites. You are in a bad place if you even consider. Maybe the big rewrite means the company has an 80% risk of going under. Still could be that safe bet.