It's all based on the dev's experience. A beginner always faces trouble estimating a feature/project, but seniors don't, cuz they have the experience to get over the hurdles in software development.

Personally, I've seen most estimates miss - even with highly skilled senior devs.

We found that quite often our projects were done on time, but if we looked back and compared how time was distributed - often the task we estimated to 4 hours would take 16, and the other way around, but somehow it evened out by chance.

We found that most of the time we worked on features that were unlike anything previously implemented in the codebase and hard to predict. And the times we did something where we said "Did the exact same thing 2 months ago, took 8 hours" it either went way faster (because we had a template in place) or slower (because the codebase had evolved and now quite a bit of refactoring had to be done, and each one required addition testing)