The sunk cost fallacy is the more we invest in something the harder it becomes to abandon it
The further into a project you are, the harder it is to change course without feeling like you’ve failed or wasted time or money.
Don’t keep working on a feature you have designed for hours if it is found to not be useful, work on something that positively impacts users.
Avoid this by breaking down work into small phases, evaluate often and have defined points to decide if this is still the right thing to pursue.