BRRRR scaling and velocity

[Catalin B.]

Hi, I am new to investing and I have the following question...

I do understand the BRRRR strategy for both SFH and MFH and it seems that many investors prefer BRRRR route vs the buy and flip... However, it seems that the average cash flow for one door could range anywhere from $100/month to $400/month or even $500/month (probably rare)...one needs to scale up to 50-100 doors portfolio in order to have a pretty decent passive income...How did you do it? How hard was is it to scale? How long did it take to reach a pretty good size portfolio?

I am trying to get feedback and advice from experienced investors success stories (or failures...that might help too)