The shift towards relying on first-party cookies will heavily favour large companies that have the most access to first-party data. These companies will have the resources to develop the most effective algorithms for maximising profits with just first-party data.
Smaller companies that lack first-party data will struggle to target and remarket to shoppers, making it harder to advertise. Small businesses will still be able to make use of technology such as Google Topics to segment users into interest groups and leverage data that way.