#2 Chance to improve form

The EFL Cup is a welcome distraction for teams that are struggling to put together a run of form in the league. It helps in banishing the demons of the league and regaining some vital confidence in an environment where consequences are not massive.
It is also a great help for teams that are playing well to improve upon their performances and ride the confidence gained from progressing in cup competitions. The EFL Cup has often seen shock results, and they reverse the tide for many sides who gain a lot of motivation from doing well against bigger sides in the cup tournament.
Managers might view this cup as a distraction, but a much-needed win often comes in this cup, accompanied by relief and some joy for supporters. The flip side, is that a poor performance can threaten to even derail the season for a little while.
The most recent example was Everton last season. Losing to Norwich began a torrid run of form that included a loss at home to Watford, and was only ended in December by an Ashley Williams inspired last-minute victory over Arsenal.
So the EFL Cup does make a difference to the season and is therefore completely worth paying attention to as a fan and a club.