I'm from Indiana. The price difference between a 1br and 2br is sometimes small. Sometimes you can get a 2br cheaper than a 1br, and sometimes both of these options run the same as a small studio in an apartment complex.

There are slightly fewer 3br apartments there, so sometimes those prices are higher. Of course, in many small-to-midsize towns there was the options of renting a trailer for the same price as the 1-2 bedroom apartments.

One city was an exception: A college town I lived in. It was fairly common for rent to go up with each inhabitant because they were accustomed to making separate leases for each student. Mighty expensive when renting to a family, but made sense for their normal renters.

I think the person above you is literally saying that in places where it’s cheap enough a single income earner can easily get a 2br. I don’t know how true that is but I believe that’s what they were saying.

Definitely doable if you're not in places where real estate has gone completely bonkers. There are lots of places where it isn't unreasonable to rent an entire house on a single income, even though most incomes there are fractions of a Bay Area salary.