Almost all the cases of countries going from underdeveloped/developing to developed did it through various forms of protectionism: Japan, Singapore, Taiwan, South Korea, China, Hong Kong.

I'm trying super hard to think of a country that did it by liberalizing fully. Eastern European countries might be the examples you're looking for, but it's too early to say.

If you think about any sport, or any activity in general, it makes sense. You never expose the hard parts, you only expose what you can easily defend or what can defend itself. Or if you're China, you fake exposing the soft parts and then you catch everyone in your tar pit :-))