Some time ago, the Russian Wikipedia conducted a survey regarding the ban on the creation of articles by unregistered members and new members. There was support for the view that based on a survival analysis of articles, this is not a bad idea.
Survey: https://ru.wikipedia.org/wiki/%D0%92%D0%B8%D0%BA%D0%B8%D0%BF%D0%B5%D0%B4%D0%B8%D1%8F:%D0%9E%D0%BF%D1%80%D0%BE%D1%81%D1%8B/%D0%A1%D0%BE%D0%B7%D0%B4%D0%B0%D0%BD%D0%B8%D0%B5_%D1%81%D1%82%D0%B0%D1%82%D0%B5%D0%B9_%D0%BD%D0%BE%D0%B2%D0%B8%D1%87%D0%BA%D0%B0%D0%BC%D0%B8
Analysis: https://ru.wikipedia.org/wiki/%D0%92%D0%B8%D0%BA%D0%B8%D0%BF%D0%B5%D0%B4%D0%B8%D1%8F:%D0%92%D1%8B%D0%B6%D0%B8%D0%B2%D0%B0%D0%B5%D0%BC%D0%BE%D1%81%D1%82%D1%8C_%D1%81%D1%82%D0%B0%D1%82%D0%B5%D0%B9
The final survey is now being conducted, which will allow an experiment for 6 months with a ban on the creation of articles: https://ru.wikipedia.org/wiki/%D0%92%D0%B8%D0%BA%D0%B8%D0%BF%D0%B5%D0%B4%D0%B8%D1%8F:%D0%93%D0%BE%D0%BB%D0%BE%D1%81%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D1%8F/%D0%A1%D0%BE%D0%B7%D0%B4%D0%B0%D0%BD%D0%B8%D0%B5_%D1%81%D1%82%D0%B0%D1%82%D0%B5%D0%B9_%D0%BD%D0%BE%D0%B2%D0%B8%D1%87%D0%BA%D0%B0%D0%BC%D0%B8