Reblogging because I work in a public library and have been asked about this, too, and I thought I'd share my two cents.
I am a library paraprofessional (no MLIS but do similar work to a librarian, and had a semester-long training required by the state).
Public library jobs are getting harder to find. I'm in a golden handcuffs position of being well paid for my profession and region, but if I went anywhere else I would be paid substantially less, enough to not be able to afford to live in this region.
Public libraries are definitely not in a great financial space right now. If they're tax funded, in some regions their budget is getting slashed. If they get funding from other sources, money is tight for everyone right now, so it's not great.
In my area we have more library professionals with MLIS degrees than available jobs (my system has one open to the public right now, and we have over 20 branches). My system is saving money by not hiring for the 50+ openings and actually just got rid of five FTEs (full time equivalent positions, which was 10 part time positions).
For a realistic idea of what I do in my work, here's some info:
I work in a large, two level urban branch.
When I am working in the adult section on the reference desk (usually the majority of my day), I spend about 80% of the time answering computer and printing questions. A lot of my other work is checking in people for study rooms. I get 1-3 "reference" (where is this book, can you recommend a book) questions a day if I'm lucky. I didn't have any on the adult desk yesterday. I am an adult "specialist" so I work the adult desk the majority of the time.
I sometimes work in the children's room, which is mostly reference and refereeing some special spaces. I love the reference part.
I am supposed to help with programming (a personal passion), but I currently have one program a month. Technically I help with a lot more but they are run by volunteers. In my system we run very few of our programs because we don't have enough staff (especially in my branch).
In addition to all of this, the main thing impacting my work is the fact that if there is an underserved population, they will be in the public library. This means I'm working with folks who have untreated mental illness (and mostly my coworkers' ableism, as 90% of the the time everything is pefectly fine), unhoused folks (again, it's my coworkers that are the problem), and anyone else the system leaves behind. It's a lot mentally, especially because we're not trained or supported in these areas. The burnout rate is high in staff. We're the last "third space" where anyone can be safe. I'm not complaining about it, I truly love it, but we don't have enough staff or general support to be able to sustain it.
Also... public libraries are really behind when it comes to disability. We do a lot, but we're shit. I'm disabled myself and a lot of the disability trainings have been outdated.
If I have to move out of state, I'll consider it. I wanted to work in museum education, but couldn't afford the degree, and there are no jobs in it right now (and they would be a significant pay cut). Right now, my golden handcuffs job would only give me a pay increase that wouldn't be much of anything, not enough to pay for the degree (especially from the closest library school). I have the money now (married a tech guy), but I don't see the point because I'm passionate about *my* job, but I just don't think a library job is sustainable for *me* in the long term.
As far as your biology degree, I'm in biotechnology central in my region and the jobs aren't really there. My younger millenial generation was the first part of the great push towards STEM, and there are more people than jobs. Also you're probably going to need a Master's degree, from what I've seen. Then again, when I came out of school, that was basically what I found with every job....