Hi!
I wanted to reply to this because I feel like I might be able to give you a little advice.
So I was an '18-'19 SMP. I had a 3.27 cumulative uGPA but my science GPA was significantly lower. I applied while I was in the program, but I have to agree with you, it was a waste of money. In my opinion, you're much better off just waiting until you finish the program to apply. I say this because med schools want to see how you perform throughout the SMP. Unless you're already a stellar applicant with just one downfall, getting accepted while you're in the SMP is really hard.
As far as the cut-throat environment, this is true. However, it is easy to find your group of people and stick with them. I had a small group of friends that I studied with and we all did very well. This program is what you make of it. If you study incredibly hard, odds are, it will pay off.
I was accepted this cycle after completing the SMP and taking another year off. I do have quite a few significant ECs...so keep that in mind. But overall, I know I would not be in if it wasn't for this program. Hope this is at least slightly helpful.