I have had success using Perplexity.ai to create a JPL file for me which works just fine with Joplin. In other words I'm using AI to create the plug-ins I want. As an example I just created one that imports a GEDCOM file so I can have my family tree in Joplin.
The reason I haven't published these is because I don't have time to maintain them and I don't want to put other uses at risk with a faulty plug-in. But for personal use, this is great. I'm sure other AI services work as well.