An interesting meta-section in the Wikipedia encyclopedia is a Wikiproject. In contrast to the portals, most wikiprojects are available today. That means, it's a barrier to put a WIkiproject into the deletion discussion. On the other hand, the propability is high that this will happen in the future, because a WIkiproject has the same problem like a portal: low amount of users, and low benefit for the overall Wikipedia.
Instead of arguing pro WIkiproject deletion, it make sense to use the time to hear what the experienced users from Wikiproject have to explain why the project make sense. The interesting point is, that Wikiprojects are the key for reaching an audience in the university. The Wikiproject medicine for example was used sometimes by medical students in courses. It's a low entry option to become familiar with Wikipedia.
Let us investigate what medical students are interested in: they are not motivated to learn something about physics nor computer science, but they stay within their own subject. If somebody studies medicine he likes to read books about it, and that means, only books about medicine. So it's a natural choice to create a subpage in Wikipedia to coordinate a team of medical students who are interested in improving existing articles. That is basically spoken the idea behind Wikiproject and the reason why they were founded in the past.
Suppose the idea is to delete all wikiprojects, what is the future participations of medical students in Wikipedia? On the first one a deletion, would block all efforts to contribute to Wikipedia especially if the own domain is focussed on a single subject. Perhaps it make sense to go a step backward and describe what science in general is about. The idea behind science is to become a specialist on a single subject. The idea is to reduce the scope. The question is, where is the right place in the Wikipedia project for doing so?
The answer is very simple: Reducing the scope is done with keywords. A keyword like “Immune System” is more specialized than the general term “Medicine”. Contributing to the Wikipedia project is possible with article request, maintenance request, deletion request, peer review request, and photo request. That means, the user has to open the page and put in the term into that page. For example, the article request page contains of all the domains, like physics, literature and medicine. What the user is allowed to do is to put his specialized keyword into the section “medicine” in the article request page.
This sounds a bit complicated but it's equal to tag a request. That means, all the request are handled as request but they are tagged with domains like physics, medicine and literature. This kind of interaction provides the same feature like a wikiproject but is adressed to a broader audience. The advantage is, that all the users have to observe the article request page. That means, even non medical experts are allowed to enter new article requests.
The wikiproject concept is equal to a decentralized project coordination. The idea is to split the Wikipedi a into sub-sections which are domain specific. This produces a lot of inefficiency. The better is to centralize the requests and tag a request with it's domain. That means, if a user likes to improve the project, there is only one page available which is the request directory. And all the issues are put into this single page.
The effect is, that the page view is higher, more people will monitor this page and the productivity is better. Wikipedia is on a path towards this goal. Since mid 2019 many portals are deleted already and in the future, the wikiprojects will follow. The switch from decentralized requests for writing new articles into a centralized request page will make Wikipedia more professional.
Let us imagine how a medical student can contribute to Wikipedia. What the user has to do is to find a very complicated medical term which has no WIkipedia article right now. This complicated term is put into the article request page, because Wikipedia should be explored into that direction. The same user can write the article for the term, and if he is done, he deletes the term from the list. The trick is to put only terms on the list, which are specialized. That means, it is not directed towards a mainstream audience but the amount of papers about the term is very low. The resulting article will attract very few readers. At the same time the reputation for creating such an article is high. What researchers are doing is to aggregate knowledge about a complicated seldom used term from a specialized domain.
Let us take a look into the reality to determine if the proposed workflow make sense. https://en.wikipedia.org/wiki/Wikipedia:Requested_articles/Medicine is the request page for all medical terms. It has a pageview of 2 per day. Which is very low. It provides a links to other languages like English. And it has some keywords like “Marshall protocol” which is a specialized subject within immune system diagnosis. According to the changelog the page isn't edited very often.
In contrast, the Wikiproject Medicine has a dailypage view of 86. And in the talk section, lots of domain specific discussion is available. It seems, that today, the decentralized wikiproject medicine is more attractive to the users, than the centralized version. The problem with the Wikiproject medicine is, that even this specialized portal doesn't fulfill the needs of the users. So they have created many subprojects: Wikiproject Anatomy, Wikiproject Physiology and so on. THe result is some kind of WIkiproject spam, in which the amount of projects is growing, but the team behind it, is doing nothing. On the other hand, i think the Wikiproject idea is a good possibility to learn because it shows, what the users are interested in. In most cases the idea is to specialize on a single subject which is a good idea because this will bring science forward. Let us click on the item Wikiproject anatomy and observe what comes next. In the anatomy section a new subfolder waits for the user, it's called Category:Anatomy articles by topic, that means, the user can decide if likes to read articles about subsection of anatomy.