Google rewards the most well-branded sites with relevant content. It's been said before, but if you write the most informative or relevant medical article on topic X for your paid domain, it still won't rank as high as a mediocre article on topc X on WebMd. So it is content plus authority/reputation that creates a higher ranking outcome.
A major change that has recently happened is that Google no longer automatically gives a high authority credit to a free property url or sub-domain as it did in the past. Third party sites that try to measure authority with their own metrics (Moz, Majestic, Ahrefs etc) have had to modify their systems to adapt to the change. Subdomain blogs that used to have a day 1 DA rating in the 90's nowstart much lower, the high TF that used to autmatically be credited to a subpage off a high TF domain now show a goose egg of 0, and so on.
You now have to build the authority of your content up page url by page url, with smart on and off page SEO applied to rank in each case, not from working on the home page or root domain. People typically expend that effort for sites they pay for, not for a free property. But if you work on building authority bysupplying serious content and backlinking for the bloggers, instead of still expecting the strong authority to be baked in (just because it's blogspot or wrdpress), you can rank for those blogs as well as you could for a paid domain.
