> SO users are still serfs building them a dataset for sale
That is a very negative spin.
Users get access to other people's answers for free. They get that free service and are required to contribute nothing. Those that do contribute do it to help other users. S.O. isn't doing anything bad. They're providing a free service where everyone wins. Users get answers. Answerers get to help other humans at scale. S.O. makes a little money.
As for the dataset, it's been available under CC-BY-SA for years. The entire database is backed up and made available here for free every month.
https://archive.org/details/stackexchange
There are even free tools to query it here
https://data.stackexchange.com/