Who will create forum for a community if one has to deal with all the bureaucracy, "right to be forgotten", data accuracy checks, data export request, gathering consents, being responsible for bugs in some forum software if there will be data leak and risk huge fines if something is not done correctly.
Another issue is vagueness of the regulation. What exactly is data processing/controlling? If kids leave they clothes in kindergarten or school, can clothes be signed with kid first and last name (so it is easier to find lost items)? Is school a processor or controller of kids' PII in that case? Probably not, but who knows what will happen if someones signed hat will be stolen?