Let's say the project was first proposed in January 2021. Got estimated as taking a year. Didn't get scheduled, since that was seen as too long, and there was other stuff people wanted done in 2021.

It's pitched again in June 2021. Same story.

Come Feburary 2022, it's pitched again. Now it's estimated as 15 months - there's more to do since more code has been written in the meantime! - and gets started, and ends up taking 19 months (estimates are never perfect!).

You might say "this was stupid, we should've just done it in January 2021" but in the cases I've seen, pushing it off a few times made perfect sense. The payoff wasn't seen as the most valuable thing that could be done, and the effort was high. The effort became higher after it was postponed, but by that point so was the relative value compared to other proposed projects.

On the other hand, if you hadn't come up with that first estimate, maybe the assumption is "ok this will take several months but we'll still be able to do this other stuff in 2021", but instead you work on it throughout 2021 and ship it in March 2022 or so (so ~15 months, still faster than doing it later), but that causes you to not do 80% of those other things you thought you could do.

Postponement or cancellation of a project because it's just too expensive to be worth it right now is a perfectly valid use of an estimate!