Did you know that you get paid for doing research while getting a PhD in science? It's basically a job! It's a very low paying job, but the job typically covers health insurance and tuition!
Most people get a PhD in science because they want to continue doing research as a postdoc then professor. Others get a PhD because they want to teach at the college level (typically introductory courses such as any courses at a community college) because a master's degree may not be enough to beat the competition.
A year or so after my master's degree while working on my PhD, I realized that I didn't want to do research my whole life and that my passion was teaching. I still got a PhD for many reasons: I greatly enjoyed being a student, the experience of doing research to help science was fascinating, I wanted to finish what I started, I was capable of doing it, a PhD can open up doors in the future, I would likely regret quitting for the rest of my life, and I was paid to do it! I was working part-time at Central New Mexico Community College (CNM), so I was also gaining teaching experience at the same time!
A PhD helps me as a teacher. I can better advise future scientists (and future engineering PhDs). Having seen how math, technology, and science are useful, I have a better sense of what material I should emphasize for various groups of students based on what their futures will require. I have learned to value a broad diverse set of knowledge in addition to being able to carefully handle complicated calculations/arguments.
I like to think that I either have the correct belief about a scientific topic or am intentionally uncertain. Having correct beliefs about science is helpful for me as a teacher in a world that so often rejects or ignores facts. There is nothing like working years in scientific research to teach us how to reject incorrect scientific beliefs since the whole business of research is to sort fact from fiction based on what can be observed. Finding a person with a PhD in science who has silly beliefs about science is much more difficult than finding someone with a master's in science with silly ideas, though I have met a science professor or two with a few bizarre beliefs (for example that dark matter does not exist). To the credit of these few professors, their odd beliefs were not closely related to their field of expertise. By the way, MDs and engineering PhDs can also very often confidently have bad scientific beliefs because they are not trained to be scientists. I am of course not talking about making silly mistakes or not remembering something correctly, which every human does. And beliefs are different from exploring ideas. A person should be fond of the idea they are exploring without actually believing it because we all need a working system of tentative beliefs to explore anything or make any decision. I love speculating, and science depends on imaginative ideas being speculated, but I certainly do not believe these speculations with any certainty. Speculation then exploring the idea are just the first few of many steps before believing is appropriate. If getting a science PhD is a painful process, it may be a good kind of pain as we learn to test and question over and over and deeper and deeper. A PhD gives us the asset of thick skin.
Here is another person's story that is more typical of a PhD student in physics.
Should you get a PhD in science? Probably not. Do you love the subject matter? Then maybe you should! Do you also love doing research? Then you should! Just keep in mind how competitive the field of science is. Far more PhD's are produced than research positions. You will likely have to move around the country or world many times to various postdoc positions before getting a tenure-track position, and you will be working many hours a week trying to publish as much as you can and write as many grant proposals as you can. If you want to start a family through this, you can, but it can be tricky. While a PhD opens some doors outside academia, it closes others due to you being overqualified.
If you are interested in using computers to simulate various scenarios of dark matter, then maybe you would enjoy research similar to mine. Regardless, you may be curious to see the type of work that goes into a physics PhD! So, see the links below. The average in the United States to be in graduate school for a physics PhD is 6.5 years (includes time getting a master's). If the links below seem beyond your abilities, that's because they presently are! But, after 4 years as an undergrad then another 6.5 years, you most likely can write a dissertation and get a PhD!
Prospects for Discovery of Dark Matter Annihilation to Primary Neutrinos with IceCube (2013):
https://events.icecube.wisc.edu/contributionDisplay.py?contribId=52&sessionId=6&confId=46
Prospects for Discovery of Dark Matter Annihilation to Primary Neutrinos with IceCube (2013):
http://public.lanl.gov/friedland/info13/info13talks/Knockel-INFO13.pdf
Distinguishing Neutrino Mass Hierarchies using Dark Matter Annihilation Signals at IceCube (2015):
https://arxiv.org/abs/1506.08285
Indirect Signals from Solar Dark Matter Annihilation to Long-lived Right-handed Neutrinos (2017):
https://arxiv.org/abs/1612.03110
Probing Dark Matter-Neutrino Connection via Indirect Detection Experiments (2016):
http://digitalrepository.unm.edu/phyc_etds/107/
My slides for my dissertation defense may be more interesting. (Feel free to ignore the backup slides at the end.)