Why do people say “don’t sell your Bitcoin, borrow against it instead”?

I keep hearing this advice to not sell your Bitcoin, just borrow against it.

But honestly I don’t fully get why that’s supposed to be better. If you sell BTC after it’s gone up, you’re actually locking in profit. You bought at one price and sold higher, so you walk away with real gains.

When you borrow against your Bitcoin though, you’re taking out a loan that you eventually have to pay back plus interest. So in my head it feels like you’re not really gaining money, you’re just accessing cash temporarily and then paying for it later.

I get that people want to keep their BTC long term and stay exposed to the price going up, but if the goal is to actually make money, wouldn’t selling a portion make more sense?