A big problem when you're a more experienced engineer is when you have your hands in a lot of things and know the relative priority of stuff and how likely it is that something else of importance will pop up. So you anticipate things getting sidetracked over time, and try to make a bit of a longer estimate, usually to give yourself the slack to do other important things without looking like you're falling behind in JIRA.

Giving an "if I had nothing else going on" estimate can be a big trap to fall into - they will only see the number and judge your performance based on that. This dovetails into the problem that untracked but still important work being thankless in low trust environments - not all work can ever be tracked, or else the time to track that work would take as long as doing the work. Examples: literally any emotional labor, time to monitor, time to train, time to document when its not explicitly required, time to solve little problems.

In the environment where none of this counts because its not quantifiable, everyone with knowledge makes themselves into a silo in order to protect perceptions of their performance, and everyone else suffers. I'll go even a little further to say that companies that attempt to have no untracked work are by nature far more sociopathic - thus far there's basically no consequences for sociopathic organizations but I hope one day there will be.