CCPA does not restrict the collection or processing of personal data for marketing purposes. You can't even opt-out. Companies like BounceX will still be able to deanonymize 40% of consumer web visitors for direct marketing. You can only opt-out from your data being sold. And how are you supposed to know when a company is selling your data? The company is not required to tell you – you have to ask.
GDPR the other hand is entirely opt-in. Companies cannot collect or process personal information unless given explicit consent. And that's a big deal – the rate of consent is so low that many marketing projects have a negative ROI and companies stop working on them.
Enforcement will likely be weak. CCPA introduces civil penalties so consumers can sue companies, or join class action suits, but it will be difficult for a consumer to know when a business is violating CCPA, so this will be rare. California's AG can bring action, but there isn't a very strong incentive for them to do so with the exception of high-profile, politicized cases.