As I said in another comment, the GDPR protects people. And the GDPR only applies to personnaly identifiable data (IPs, email addresses, street address, legal name, date of birh…) Lemmy only collect emails and IPs, and do not share them between instances. So it’s very easy to comply to the GDPR as long as you don’t do anything shady.
The EU has a marketing issue. They tried to pass legislation to prevent companies to collect data. But instead, company displayed a popup, kept collecting data, and blamed it on the EU. Everytime I see a popup, I blame ruthless data collection.
Actually, Lemmy is most likely violatiing the California Consumer Privacy Act, which, as opposed to the GPDR, gives the right to update/delete any data generated by the user, not only personally identifiable information.