I'm both surprised that people react so strongly and... mostly ok with it. Majority of GDPR is pretty reasonable - know what data you have and make sure your users know it as well. Allow removing it, make sure you don't share with parties who don't need it. For normal services it doesn't appear to be a tough retirement.
You certainly don't need to hire extra people like author suggests and federation should be just fine. (it's essential to what the service does)