It is all about the openness and complexity of the technical interfaces, INCLUDING THE SDK (Software Development Kit).

Those interfaces must be straight to the point without convolution, I should be able to write assembly code which would implement directly those interfaces, that with some reasonable amount of effort.

This is a good benchmark, even though there are always ways to sneak complexity somewhere, namely stay focus on the dependencies of those interfaces, absolutely including the SDK.

If they cannot trick you, they'll go super aggressive, be careful.