On a team where Agile is the goal (not reality) for project management, I often feel inclined to help others with their work when I have spare time. Unfortunately, this sometimes means I become the owner of work that was poorly scoped and thus I start failing to meet the deadlines that the previous owner gave to customers.
For example, imagine a coworker was asked by a customer to onboard a new data source for the platform. They scope based on a demo-quality setup based and give a week estimate, then they ask for help during stand-up and I offer help (sometimes I'm just told/asked).
Quickly I become the owner and I realize that the original scoped work is lacking in all sorts of quality management like unit/integ tests for the webscraper, testing for the database schema, dev/beta/prod staging, etc. So the original week deadline will not be met if I sacrifice quality. Quality is a recurring issue that eats ~30% if bandwidth when things break.
Furthermore, my projects get pushed back leaving a trail of unfinished work because I keep getting moved to the next high priority to save the day.