don't sell your bitcoin, borrow against it

I don't understand why it's "better" to borrow agaisnt your bitcoin instead of selling.

I understand that selling btc is not ideal when you want to keep them as long as possible, but If the goal is to make money with bitcoin, then selling makes more sense, no?

What's the point of borrowing money and pay back the debt + interest?
It's not like you're getting money, because you'll have to pay back the loan anyways. Looks like a zero sum game to me (even a loosing game because of the interests).

Where if you sell your btc at profit you actually get more money than what you initially invest, so you're actually earning something.

I think I'm missing something.