For us, an accurate delivery date on a 6 month project was mandatory. CX needed it so they could start onboarding high priority customers. Marketing needed it so they could plan advertising collateral and make promises at conventions. Product needed it to understand what the Q3 roadmap should contain. Sales needed it to close deals. I was fortunate to work in a business where I respected the heads of these departments, which believe it or not, should be the norm.
The challenge wasn't estimation - it's quite doable to break a large project down into a series of sprints (basically a sprint / waterfall hybrid). Delays usually came from unexpected sources, like reacting to a must have interruption or critical bugs. Those you cannot estimate for, but you can collaborate on a solution. Trim features, push date, bring in extra help, or crunch. Whatever the decision, making sure to work with the other departments as colaborators was always beneficial.
There are problems with all of these. The company knows they can sell X of the product for $Y (often X is a bad guess, but sometimes it has statistical range - I'll ignore this for space reasons but it is important!). X times Y equals gross profit. If the total costs to make the feature are too high the whole shouldn't be done.
If you trim features - the affects either the number you can sell, or the price you can sell for (sometimes both).
If you push the date that also affects things - some will buy from a competitor (if possible - and the later date makes it more likely the competitors releases with that feature).
Bring in extra help means the total costs goes up. And worse if you bring them in too late that will slow down the delivery.
Crunch is easiest - but that burns out your people and so is often a bad answer long term.
This is why COMPANIES NEED ACCURATE ESTIMATES. They are not optional to running a company. That they are impossible does not change the need. We pretend they are possible because you cannot run a company without - and mostly we get by. However they are a fundamental requirement.
Sure, but even accurate estimates are only accurate as long as the assumptions hold.
Market conditions change, emergency requests happen, people leave, vendor promises turn out to be less than accurate.
And most estimates for non-routine work involve some amount of risk (R&D risk, customer risk, etc.).
So pounding the table and insisting on ACCURATE ESTIMATES without a realistic backup plan isn’t good business, it’s just pushing the blame onto the SWE team when (not if) something goes south.