[whynotmaybe]

The 3 reasons I've seen for failure :

1 - management want to add something to the requirements so they can "shine" and grow their career = why some almost never used basic crud internal app for 7 users is built with docker, microservices and redis.

2 - management don't want to take the necessary risks because they fear that might taint their career if it doesn't work = why we still have cobol code from the 60's

3 - incompetent people, I even found some saying about this "it only needs the bad person at the right place for wreck it" = don't get me started on that one.