Ghostery used to belong to a company named Evidon, which had this business model of collecting data to sell it in some form (the feature was called "Ghostrank"). In 2017, Ghostery was acquired by Cliqz (which builds an independent and private search engine from Germany), and since then a few things happened: (1) the extension was open-sourced, (2) Ghostrank was completely removed and (3) Ghostery is now developing paid products as a business model. For example we launched Ghostery Insights[1] and Ghostery Midnight[2] recently, both of which are subscription-based.
[1]: https://www.ghostery.com/insights/ [2]: https://www.ghostery.com/midnight/
It would be interesting to know which other privacy plugins that sell data. Current recommendations seem to be pretty unanimously favoring plugins which do not, but it is always a moving target.
In addition to my answer regarding the business model of Ghostery above: https://news.ycombinator.com/item?id=21897809. I'd like to add a few things to address your points:
(1) Ghostery did not "fall completely out of favor", as far as I can see. It is true that in _some communities_ (in particular some sub-reddits), some people tend to recommend different addons instead (often not based on any technical arguments, though), but this is not a trend that can be generalized (more people continue to recommend Ghostery as a very solid privacy protection suit).
(2) EFF's Privacy Badger is not a replacement for Ghostery, for more information about why, we wrote about it in the past[1][2].
(3) Ghostery has an "actual ad-blocker" built-in, in fact, it is one of the most efficient out there as was shown in a study that we published this year[3]. The adblocker as well as benchmarks are open-source and anyone can run them locally to verify the claims. We also more recently wrote extensively about the internals of this adblocker[4].
References:
[1]: https://whotracks.me/blog/how_cliqz_antitracking_protects_us...
[2]: https://0x65.dev/blog/2019-12-19/blocking-tracking-without-b...
[3]: https://whotracks.me/blog/adblockers_performance_study.html
[4]: https://0x65.dev/blog/2019-12-20/not-all-adblockers-are-born...