honestly how would i be successful at a youtube channel?

Finding your niche doesn't mean swimming away your competition.
Its about finding a balance between what you love to do and what you can do and how good you do it.

Eg:
Lets say your niche is being a lifestyle vlogger like Casey Neystat, Oh the spot is already taken then why are there so many good vloggers.
Understand this and believe in it. There are 7 billion people on this planet and you just need 1 million followers to call yourself sucessfull.

how difficult is it anyway if you do it right.

I did the same mistake of disowning my mistakes and shutting projects on and off because of insecurities, fear of judgment and what not.
If I kept all that content I would have had a very strong thought leader footprint and I could have leveraged on that. But I disowned them which is a mistake now I feel.

After reaching a point of professional understanding of how personal branding and content marketing works.

what every you do how many twists and turns you takes. how many pivots you make.
be authentic, Be real and stay true to yourself. It should all work out.

Just Do iT and Keep Doing It.

Cheers