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.
My favorite metaphor is building something like a new shopping mall. If you ask for an estimate you first need to architect the entire thing. This is equivalent to breaking down the task into sprints. In most companies the entire architecture phase is given very little value, which is insane to me.
Once we have our blueprints, we have other stakeholders, which is where things really go off the rails. For the mall, maybe there is an issue with a falcon that lives on the land and now we need to move the building site, or the fixtures we ordered will take 3 extra months to be delivered. This is the political part of estimating software and depends a lot on the org itself.
Then, finally building. This is the easy part if we cleared the precursor work. Things can still go wrong: oops we hit bedrock, oops a fire broke out, oos the design wasn't quite right, oops we actually want to change the plan.
But yes, estimates are important to businesses. But businesses have a responsibility to compartmentalize the difference. Get me to a fully ticketed and approved epic and most engineers can give you a pretty good estimate. That is what businesses want, but they consider the necessary work when they Slack you "how long to build a mall?"
Whereas with software most of what was done previously is now an import statement so up to 80-100% of the project is the novel stuff. Skilled leaders/teams know to direct upfront effort toward exploring the least understood parts of the plan to help reduce down-stream risk but to really benefit from that instinct the project plan has to regularly incorporating its findings.