For the record, I think GitLab is awesome :) There's a ton of amazing reasons for large companies to use GitLab (storing your own data, customization, etc) that I completely stand by.
My umbrage is simply with the price argument Gogs lead with; it'll always end up cheaper to use GitHub (or another hosted solution) than to run your own.
That's true if you're running a typical business. But there really is a whole other world that opens up when things are free.
Maybe you are a young person, and don't have access to online payment methods. $84/year or more could be really significant for a 15 year old, or someone in a country that Github can't legally transact with.
Or maybe you need to roll your own hosting solution. Maybe for security, maybe you're integrating with APIs like a corp SSO that are not on the public web, etc.
We do a few wacky things in our business (test infrastructure SaaS) and sometimes we need to do stuff at scale where all available commercial solutions assume a single user. Open source solutions are a godsend there. We don't have that need for code repos (we use Github) but I can totally see why others would need it.
My umbrage is simply with the price argument Gogs lead with; it'll always end up cheaper to use GitHub (or another hosted solution) than to run your own.