I think that one that is angry about paying 30 for avocado toast should make their own for five bucks and tip themselves.

I mean, that's on you for agreeing to pay $30 for an avocado on toast.

I'm against (forced) tipping culture but the waiter is not at fault for the prices a restaurant sets up. If I saw the price and still decided to order it, I will definitely not fault the waiter for it.

Waiters that give great services gets tipped because I want to encourage waiters to give great service.