What I did: EMT-B in my first year of college - Paramedic after college - worked for years - finished med school
There are about a hundred very different issues going on in this thread, and I can sense the OPs confusion.
It seems the OP started with asking if the BS in EMS is a good idea for an undergraduate degree, leaving open the possibility of med school in the future. In short, it is. But, a bachelors degree vs. a medic cert are two separate issues, and everyone's only hitting the medic issue.
A BS in EMS (or Emergency Management... or whatever) is a good idea if it is from an accredited college/university like UMBC or UT. It is more than worth the paper that the diploma is printed on. Understand that you will be completing an accredited bachelors degree of ~120 credits. An EMT class or required clinical time may be only 3 credits per semester. Your other credits will be in statistics, history, bio, chem, health policy, psychology, politics, etc - a bona fide bachelors degree where one third is in the major area of study, one third in liberal arts/general education, one third in elective or minor area of study. There's nothing wrong with this whether you are going to med school, or not.
A Bachelors degree will help you get into med school. A medic certification will not. A medic certification may not even help you in med school - in that, knowing how to start an IV might save 5 minutes of your time, but having been in charge of reviving a patient in cardiac arrest dozens and dozens of times may make you feel better when you are the lowest guy on the totem pole in a Code in med school. But I can assure you that nobody will notice that you aren't sweating. At best, someone may ask you if youve taken an ACLS course before... get my point? EMS and Medicine are vastly different. As different as being a sports journalist and a baseball player. Both "know" baseball, but in two very different ways. And one is not "better" than the other. Its not "going for the gold". Its going for something which is more intellectually challenging and time consuming... not gold per se.
Also understand that EMS is incredibly region-dependent in how you are trained, what you can do, and even how closely your job relates to Emergency Medicine. In some places you are a Firefighter who can put an IV in somone. Where I worked, you are the eyes ears and hands of the Emergency Physician who you are transporting the patient to. You'll have to figure out if your particular setup will help you get to where you want to be.
There are plenty of other ways to become a medic as many others mentioned, but none of those seemed to be part of your plan. Thats fine. You arent sure if you want to be a medic or a doc.
To me it seems like you're slightly interested in EMS and slightly interested in being an emergency physician. In my experience, and what Ive seen in others, testing the waters of EMS and trying to extrapolate that to wanting to be an Emergency Physician is a HUGE mistake. On one hand, "seeing if you like" EMS rather than "training to become an EMT" means that you are going through the motions and seeing how you feel. Youre going to hate it, and ruin your whole plan. On the other hand, if you like EMS and then go to med school for that reason, you're in for a rude awakening when you have to learn about all of biomedical science, and things which have nothing to do with saving lives. If you just assess how you feel about things as they come - learning to rescue, losing sleep, getting shot at by the guy that shot your patient- you'll give up. If you take it all in as part of the job without "seeing if you like it".... you'll love it.
But here's the issue. If you dont know if you want to be a medic or a doctor, it may not be a good idea to set yourself up this way. Especially since your BS graduation requirements require you to be a medic. These programs are designed for people who want to be informed and educated in a career in EMS. Why not take a general Bio or Finance, or History degree - something you like. Take your 8 premed classes, and if you want to, the EMT-B. Why box yourself in at this point? With your plan, you arent giving yourself options, you are actually limiting yourself. Trust me on this. I'm a whole lot older than you.
OP seems to be concerned about burnout (which can be from being, overworked, sleep deprived, post-traumatic stress, or being underpaid). I dont think it makes sense to think in this way. I know both ER docs and Medics who have been doing it for 25-30 years. You do not burn out if you have no illusions of what you are getting yourself into. What really doesn't make sense is to plan to go to med school to save yourself from burnout in EMS. You'll burn out in your second semester Biochem class in med school.
Enough for now. Heres the bottom line. Youre in high school, and are looking for college major which will give you exposure to EMS and options for MD/DO. Getting a BS in Emergency Services is a viable option to do both However, the program is designed to turn you into an EMS professional who understands what its like to work the streets, as well as in the classroom, as well as in the municipal board room. Its pretty specific. If this is what you want to be able to "fall back on", then fine. But you are going all in. You aren't testing the waters.