If your goal is to be primarily a scientist, MD is not required and I would advise against it.
For the physician scientist route there is a most-traveled path:
1. get involved in research early and often
2. Go to med school
3. Do research while in med school. Get lots of pubs. Do as well in med school as possible. The better you do, the better you match, and the better the odds of high powered research.
4. Go to a residency program, either straight residency or go into a residency/research slot
5. Get as much protected research time in residency as humanely possible.
----- at this point, there are many routes. Many people have burned out from research here but some continue the forward slog.
6. After residency, go straight into a grant (likely a T32 grant) and do research full time as a research fellow (post doc)
----- at this point, many people will just flow into academia and do a mix of clinical work, teaching, research. It is rare to continue on full time research. It would be "failing up" in that you would do less research and get paid more. This is also a time that pharma may reach out for you to do full time research work for them.
7. Amass enough success in research that you are competitive for a K award (rare)
8. Take your K award into an R01 (super rare)
9. Bon voyage, you are a full-fledged god among men - a physician scientist with solid grant money and a lab. You're like 40 and your career just started. You and your family can finally afford groceries (somewhat joking). Your 20 year old toyota can finally be replaced.
It is hard to do wet lab research as an MD unless you are willing to stop caring for patients primarily. You pretty much can't do steps 6 and beyond unless you are full time research. The long and short of it, is that you will need lots of dedicated research time to be a wet lab researcher in the MD route. Any time towards research will pull away clinical time for patients.
As the folks above have said - research doesn't happen in any meangful way without grants. Thus, the pathway to getting a grant-funded lab is a slog, and takes a lot of dedication, persistance, and possibly blind luck.
Good luck.