I agree with the previous answer provided, specifically that STEM careers have longevity and there is almost always something new to learn. And for sure, one's ability to convey their STEM work in a relatable way is priceless. These things combined can lead to a pretty stable financial future.
One additional thing I will call out, specifically with respect to STEM is this idea of being innovative. I use the word "innovative" because, really, there are many ways, in the current environment where STEM and art intersect. Are you familiar with NFTs? Many fantastic artists are creating beautiful work either on canvases or in a digital space and utilizing STEM skills to share that work.
I am highly biased in that I think that STEM can be used to create and enhance just about any form of work and/or life activity. I see the creative space of art as just another amazing space where STEM can play a role. All of this to say, I don't think you necessarily have to choose between art and STEM. There is lots of room for both. That said, as you take in financial considerations, your work in STEM may require a bit more "care and feeding" to keep your knowledge and skills fresh and relevant.
I hope you find this answer helpful and I wish you all the best on this journey.
What I've also observed -- as a writer now working in data analysis -- is how narrative permeates everything. Nature is all about causes and effects, accidents and impacts and disasters and triumphs, leading to results that might be good and might be... not good. I think having a sense for those stories can help you be more insightful in almost any work.