If you had an opportunity to study AI for your PhD then it might be worth it. However, since your field is rather niche, I don't see how it would be that valuab

If you had an opportunity to study AI for your PhD then it might be worth it. However, since your field is rather niche, I don't see how it would be that valuable to industry. My advice is that you need to get out of there, and get a job as soon as possible. You will realize that what you've learned at university and real world software development are really quite different.