Depends on the nature of the work - I recently did a gig at a civil design engineering firm and multiple projects came in at or under budget and on deadline.
We’re there some serious overtime crunch periods on a couple of them? Yes, but for a multimillion dollar project with expiring Federal funds, it was achieved as set forth.
I think we tend to hear more about the failures than the successes - the Omni hotels in Houston and Dallas built with bond funds were repaid years earlier than mandated because they were successful, for instance.
Estimates aren’t necessarily accurate just because they end up being close to reality - that could just be chance. The estimate for a project that came in substantially under budget was just as wrong as one that came in substantially over, it’s just easier to live with. If all estimates are wild-ass guesses, then some will come in on time and budget, some will undershoot and some will overshoot.
I do believe that estimates, even for complex projects, are useful and can be fairly accurate, and in a lot of circumstances they can be used as the basis for deadlines, with certain considerations.
If "achieving" your estimate included a lot of crunch, your estimate was bad. A lot of poor estimation externalizes it's error to those trying to meet the estimate. Long hours, weekends, etc. over months while pretending the work fit on a nice paced 40 hour week with breaks is not a good estimate. Chances are, there's probably a lot of corner cutting in the final product as well, because your requirement set and associated deadline was the priority vs having a quality product delivered.
We’re there some serious overtime crunch periods on a couple of them? Yes, but for a multimillion dollar project with expiring Federal funds, it was achieved as set forth.
I think we tend to hear more about the failures than the successes - the Omni hotels in Houston and Dallas built with bond funds were repaid years earlier than mandated because they were successful, for instance.