The people who care about you may not tell you your blind spots fearing to offend/hurt you. Open up and ask their feedback and get enlightened.

The people who would like to manipulate and use you won't tell you your blind spots. They may plan to continue using them to their advantage.

If there're weaknesses you don't know about but others do- your blind spots, it's embarrassing. Plus, people use them to mock you and take advantage over you and your circumstances.

As a leader, 1st, work on yourself- increase your self-awareness. There shouldn't be any other urgent agenda than this. Get enlightened! Know very well who you're including your strengths, weaknesses, and blind spots!

Who knows, you may be that close. You could be uncovering a blind spot or two away to take your career to the next height...

It's not a proper feedback if it's given to flatter and/or belittle someone. True feedback should be given to empower someone perform better.