Economics generally assumes people are rational. Given the information people have they’ll make the best decisions, in a Dr Spock like fashion. It’s an ok approach, but not a great one.
One of the more interesting challenges to this model is something called path dependence. This means that the world is shaped by not just what’s the right decision for people right now, but what has gone before. There are some of good examples of this:
The QWERTY keyboard is one example, originally designed to stop keys sticking on prototype typewriters it’s now being used on touchscreens on iPads where there aren’t even any actual keys. Other keyboard types are proven to be superior, such as Dvorak, but they are not broadly used – the move away from physical keyboards to on screen ones should make switching even easier, but nothing has changed yet.
There’s a good paper on path dependence here if you’re interested in learning more about it.
The question is this, on your projects, how many things are done because they’ve always been done that way?