Just curious. What do you think it is that makes twilio a good example of a REST API? Other than the fact that they have one?

It used to always be cited as an example of a good REST API see this same question from 7 years ago and you'll see Twilio is top recommended https://news.ycombinator.com/item?id=867972

Oh and still is today because it's a good API - timeless

From a development perspective it isn't so much the actual API or the structure of it.. but how easy they make it to understand and integrate into it.

They have a plethora of getting started guides and examples that make it really easy to 'hello world' quickly.

You have to actually dig to get to the reference when you first sign up.

Hello world in 30 minutes or less is important for any API program.