It really depends on how they implement it. They can either implement it in a way that it requires such exorbitant compliance costs, that it kills off competition. If that's the case, the law will just strengthen the foothold of the current few companies and create a market without competition, which would be terrible. Alternatively, they could implement it in a way that it hurts every player in the space by making them follow extremely strict privacy and copyright laws to make it hard for everyone, but without stifling innovation.
I feel like the EU could potentially take the first route and that's scary. You can argue the EU is anti-BigTech but all those fines are just spare change for these giants, so how do we know it isn't just a smokescreen?