One big difference is regulation and algorithms. All viewers/readers see the same content in traditional media, and they’re all subject to scrutiny by government regulators (however effective or not they may be).
Social media networks display different things to different people so it’s borderline impossible to know exactly what they’re even showing. That makes regulation extremely difficult.
More broadly, this perspective depresses me. I’m old enough to remember the promise of the internet when we first all got it: that it would democratise information and we’d be able to break free of the issues with traditional media. Fast forward to today and we’re asking “why shouldn’t the tech giants monetise hate speech?”. How far we’ve fallen.