There are some situations where the non-English Wikipedias have far more information than the English ones though, because of how "notability" works.
https://en.wikipedia.org/wiki/Wikipedia:Size_of_Wikipedia
Deleting articles doesn't prevent anyone from participating, since anyone can write/edit articles on any notable subject. The deletion process protects Wikipedia from search engine marketers who try to promote their clients with biased low-quality content. They can go to Quora for that.
https://en.wikipedia.org/wiki/Wikipedia:Deletion_policy#Reas...
When I said that it "doesn't prevent anyone from participating", I was only considering the editors who are interested in writing about a wider variety of topics.
For better or worse, Wikipedia frowns on editors who are only interested in editing articles on one topic. There's a page for that:
https://en.wikipedia.org/wiki/Wikipedia:Single-purpose_accou...
This is because these editors usually have a conflict of interest, and must make an extra effort to keep their writing free of bias.
Policies aimed at improving the quality of articles also tend to reduce participation. It's a trade-off, and I don't know that the optimal balance would be.
A bit later on, there was Croteam, the maker of Serious Sam, AMA on Reddit so I asked them if the reference to Derek Smart was an inside joke or what. The reply was along the lines of "he's a dear friend of ours and our inspiration". I went back to the Derek Smart Wikipedia article, pointed out the screenshot of the credits with Derek's name, the AMA reply and asked a very innocuous question: "Can we put this in the article?"
I got a reply that what I did is termed "original research" and the only acceptable way to include the reference would be if some noteworthy third party, such as Washington Times, mentions and explains the connection, meaning all the work I did up to that point was in vain. That's when I completely gave up on editing Wikipedia as it seemed to me, and still does, absolutely Sisyphean. Editors of that article then went on to argue how to phrase the incident where Derek Smart assaulted a vending machine to best fit the article.
The implication of "no original research" and "noteworthy sources of information" means a large mass of regional events and persons can't be included in the English Wikipedia unless they clear this arbitrary bar of noteworthiness that can still be gamed with ease: a) be an employee of a mainstream news source, b) publish a biased article on any given topic, c) create an anonymous Wikipedia account, d) create an article on the topic or edit an exiting one to embed the information you published and e) marvel as Wikipedia editors revert the changes under the guise of preventing vandalism.
Automated edit-correction tools are another grave issue for Wikipedia, as they instantly revert an article to its sanctioned version set by a reputable Wikipedia editor. How is Wikipedia "an encyclopedia anyone can edit" again?