I don't think it's quite as black and white. LinkedIn is just one channel, but I imagine you're going to have a hard time finding a workplace where social credit isn't a big part of internal politics. Whether that's being charming, great at your job or using SoMe, it's all about people.

I doubt any company primarily uses LinkedIn for promotions, but it does help your career if you are known for something positive by the people who run the company you work for.

Of course social credit is a big part of internal politics, but if you have to resort to an external social network for your internal signaling, something is very broken. This whole subthread is about someone claiming they have to be active on LinkedIn to prove their worth to someone inside their organization.