My own feeling, based on nothing more than the anecdotal experience of earning a reasonable living in four separate 'careers' over the last 45 years, all without a smidgen of a degree in sight (forgive the humblebrag, but I turned down an offered place at Cambridge in favour of more vocational training) is that most people in a position to give you work care far more about whether you can actually do the thing you're applying for than whether you've got formal qualifications. In fact, skill acquired through experience is often more sought after than purely academic qualification, since it usually comes tempered by practical application of that skill in the real world.
Of course, there are exceptions, and rightly so, for careers which require intensive training and specialist knowledge... I wouldn't want to be operated on by an untrained surgeon! But, in my view, writing (along with most other creative endeavours) isn't one of those.
I think in this world, inevitably, there are people who can write and people who can't. Anyone can be taught 'how to write', of course, in the slightly reductive sense of acquiring knowlege of grammar and sentence construction and narrative structure... even 'storytelling', and come out of the process with a letter or two after their name. But I'm not sure that alone necessarily makes them a writer. It might, perhaps, help turn a good writer into a better writer. But it can't turn a non-writer into a writer.
To your question, from what I've gleaned on these forums and elsewhere, any agent or publisher will be interested solely in whether the book is a) competently written, and b) saleable, with the emphasis firmly on the latter. If it is, they won't give a damn whether the author has a degree, good or not. If it's not, having all the letters of the alphabet after your name won't help place it.
That said, it can't hurt to mention any qualification in passing in a query, I suppose, if only to show your commitment!