This kind of mass delusion has been pretty much de rigueur my entire career (decades):
Software is typically quite hard and mostly unknown at the beginning of a project. Most of the hard work is figuring out the things that weren't known. It's a learning/discovery experience. It's essentially impossible to predict how long that activity will take. The further out in time you consider, the less likely you'll have much of any clue about the subtasks to be done. And of course in the meantime the participants likely aren't even working close to 50% of their time on the new project -- instead they're fixing the bugs and technical debt in the last project.
And yet, the "stakeholders" simply wouldn't accept any narrative like the real one (we kind of have an idea how to do this but we're going to figure it out as we go and it'll be difficult and unpredictable). They'd go hire another bunch of folks who are willing to salute the flag. So instead we pretend that what we're doing is predicable and plannable, like building a bridge that's a bit longer or shorter than the last 10 bridges that we built.
The stakeholders probably have a pretty good idea that the developers are making it up as they go. But everyone behaves as if the reactor isn't on fire.
Have you spent the decades of your career working at companies that blew their competition out of the water with better software, like Google, Apple, WhatsApp, and Facebook, or at companies whose software was unremarkable or inferior? If it's been some of both, did you note a difference in the degree to which stakeholders grappled with the kind of uncertainty you're talking about?
Software is typically quite hard and mostly unknown at the beginning of a project. Most of the hard work is figuring out the things that weren't known. It's a learning/discovery experience. It's essentially impossible to predict how long that activity will take. The further out in time you consider, the less likely you'll have much of any clue about the subtasks to be done. And of course in the meantime the participants likely aren't even working close to 50% of their time on the new project -- instead they're fixing the bugs and technical debt in the last project.
And yet, the "stakeholders" simply wouldn't accept any narrative like the real one (we kind of have an idea how to do this but we're going to figure it out as we go and it'll be difficult and unpredictable). They'd go hire another bunch of folks who are willing to salute the flag. So instead we pretend that what we're doing is predicable and plannable, like building a bridge that's a bit longer or shorter than the last 10 bridges that we built.
The stakeholders probably have a pretty good idea that the developers are making it up as they go. But everyone behaves as if the reactor isn't on fire.