Not entirely sure what the commenter was referring to, but it might be about tracking (Firefox has great anti-tracking and privacy tech). The real money on the web comes from ads, and specifically targeted ads. Targeted ads require that advertisement companies like Facebook and Google track you and build a profile based on your activity. Companies like reddit make money by helping to build these profiles and by delivering ads.

If you can still be targeted by ads, the powers that be will continue to try and "make a buck" off the internet. If there is a market for targeted ads, it is likely that a service will be monetized for the sake of profit, which typically leads to situations like what we've seen with reddit, Twitter, Facebook, etc... Privacy is essentially an ad-business killer in the modern web.