This can come as no surprise. It's been almost 3 years since the GDPR coming into force, but there is still no clear understanding on how to properly anonymize data.
With huge possibilities and ways to re-identify data offered by modern solutions and tools, it might be necessary to go above and beyond to truly anonymize data, especially in complex and/or multinational scenarios or where data inventories are managed incompletely/insufficiently. And you still may end up being ensure whether your efforts were enough.
It is time indeed for EDPB to join this chat.