I've been in performance marketing long enough to see the macroeconomic cycles repeat themselves - platforms mature, costs rise, and the same "tactics" get repackaged as courses. For LinkedIn Ads, AJ Wilcox's B2Linked content is the closest thing to a map of a shifting landscape. His approach captures the B2B nuance that generic courses strip out. For Google Ads at an advanced level, Mike Rhodes and Aaron Young are worth your time - they don't just teach mechanics, they explain the auction behaviour that scales. Meta for B2B is still the wild west, but Depesh Mandalia has a structure that actually holds up under pressure.
That said, no course replaces a real budget burning through the system. The algorithmic feedback loop is the only teacher that forces you to adapt. At the intermediate stage, you're better off taking a small ad spend and running experiments in a controlled environment - the lessons stick because they cost you something.