I think there's still a lot they could stand to gain from a large & diverse trove of data - details like product BoM and production costs, supplier lists & pricing agreements, detailed product specifications, release schedules, marketing strategies, etc. These would be protected by trade secret, although I think those protections only work as long as the information remains non-public.
I'm sure they read the published leaks, just like the rest of us. I don't think they know much beyond that, again because the liability of being involved in corporate espionage is so high.
At my job, we have to take annual "ethics" training classes, where one of the things they drill into us is not to seek or use non-public information about a competitor. From what I understand, most big companies have similar programs in place. By "ethics", what they really mean is not to do things that expose the company to liability. Things like bribery, collusion, texting while driving on business trips, unsafe work practices, harassment, etc.