Feature summary (what you would like to be able to do and where):
Add a suggestion that, when there are links like [[:en:Some article in English Wikipedia|some text]]/[[:ja:Some article in Japanese Wikipedia|some text]]/etc, suggests to replace them with:

• {{iw|<how the article should be called in local wiki>|some text|en|Some article in English Wikipedia}} (for this template), or
• {{li|<how the article should be called in local wiki>|some text|Wikidata element for en:Some article in English Wikipedia}} (for this template).

Though, second can be converted from first by the bots and is a bit harder for VE to implement, so even only first would be fine.
Note that the only problem in bot conversion from plain links to iw-links is that there is no way to tell <how the article should be called in local wiki> -- and exactly that would be expected to be provided by the user.

See also a gadget for this replacement in Russian Wikipedia.

Benefits (why should this be implemented?):
The presence of plain interwiki links is considered quite a problem in Russian Wikipedia (because they confuse readers and don't allow making their experience better, unlike a template), and their number is not really decreasing (July 2024 -- 38k, August 2024 -- 45k, September 2024 -- 47k, October 2024 -- 80k, November 2024 -- 78k, February 2025 -- 70k, April 2025 -- 69k, May 2025 -- 69k, July 2025 -- 72k, September 2025 -- 71k, numbers from here). Implementing them as a suggestion would, hopefully, make this more seen to users and, as it is quite a very simple task, help to solve this problem.