Part of the problem is the tech industry. There's plenty of people trying to get rich quick in tech and LinkedIn is essentially made for them. I don't see it as much in other fields where most people don't imagine themselves building unicorn AI startups with VC money and becoming obscenely rich.
It is a way to keep up with opinions about industry news, but at least for tech, I think this is all downstream of what's happening on "short-form" social media. It breaks on Twitter and then you get LLM-powered thought leadership on LinkedIn for the next two weeks.