It really depends on what you are working on. When I did agency type of work, building things you have built before, from scratch, it's easy to estimate. E.g. some sort of e-commerce website from scratch. On the other hand, working in a large corp, with massive legacy systems, unknown domain knowledge and dependency on other teams, it becomes near impossible. What might have been a 2 hour task in agency, might either be completely impossible during our lifetime unless the whole company was built from scratch or take 2 years. You might need 6 other teams to agree to make some sort of change, and you first might have to convince those teams, and then 2 teams will initially agree to it, then pull out in the last moment, or realize they can't do it.

In your 2nd example of a large corp I can see myself joining and not knowing anything about all these potential landmines etc… but if I was at that corp for say 2-3 years those would all be known things, no? And hence estimates can come with number of assumptions based on 6 other teams doing whatever it is that they need to do etc…? But I totally agree with your point and would not be disappointed if someone missed an estimate in that sort of chaos.

My comment was not really geared towards chaotic organizations but general sense (especially in myriad threads on this forum) that SWEs think that somehow our profession is so “special” that we cannot possible know how long something will take. I simply do not accept that and personally believe that more likely vast majority of SWEs simply suck at their job. there are roughly 4.5 million of us, how many are really good at their jobs (big part of which is estimation)? probably like 0.4% :)