If you're doing something creative then deadlines can be useful to stop yourself from constantly tweaking. Actually finishing stuff helps with morale and also allows you to review and hone processes, rather than getting lost in the weeds. I dabble in music production and the amount of 16 bar loops I had before actually deciding to restict myself (with the help of a friend adjudicating) was mind-boggling. Once I'd started to finish stuff it became easier overall to not get stuck in a rabbit hole.