I know a guy with over 100 doors. Some months he clears less than $1,000.
Not

$1,000 per door. $1,000. Total. After running an entire portfolio the

size of an apartment complex, working nights and weekends, fielding

calls, chasing rent, replacing water heaters, the number at the bottom

of the page some months is less than what a lot of people make in a

single week at a job with a lunch break.
But sure. More doors.
Here's

the math not on the flyer at that REIA meetup: single-family rentals

don't scale efficiency the way multifamily does. Every door is its own

roof, its own HVAC, its own tenant, its own eviction risk, its own

vacancy period, spread across a dozen different zip codes instead of one

building. You're not running a portfolio at that point. You're running

100 tiny, unrelated small businesses, badly, at the same time.
Add

in property management fees eating 8-10% of gross rent (if you're not

self-managing yourself into a breakdown), capex reserves nobody actually

sets aside until the roof proves them wrong, and financing 100

individual mortgages instead of one commercial loan, and "door count"

turns out to be a vanity metric, not a wealth metric.
The guys selling the "more doors" dream aren't lying about the doors. They're just not the ones showing you the P&L.
Real

question to ask before you scale anything: not "how many doors can I

get to," but "how much am I actually keeping per door, after

everything." A guy with 8 doors clearing $6,000/month cash flow is doing

better than a guy with 100 doors clearing $1,000, and sleeping better

too.
More doors doesn't mean more wealth. Sometimes it just means more problems, spread thinner.