Even if companies strictly adhere to copyright protection, the negative effects of upload filters for society as a whole should not be underestimated: they will reinforce the gatekeeper position of the biggest platforms and have a big impact on the public discourse, not to mention the spillover effect on smaller platforms who will follow in order to not suffer from a competitive disadvantage.
Source: Good Ends, Bad Means? The EU’s Struggle To Protect Copyright and Freedom of Speech