Real mass-market cameras for this era would have been things like the Kodak Pony line or Argus C3 (aka "the brick"), or the brownie box cameras you mentioned.

https://mikeeckman.com/2022/05/kodak-pony-135-model-c-1955/

https://camerapedia.fandom.com/wiki/Kodak_Pony_828/135

https://en.wikipedia.org/wiki/Argus_C3

Anyway just as a general statement, photography was a mass-market thing throughout most of the 20th century - it just wasn't the glamorous pro-tier cameras that we still remember and care about today. Kodak in particular always catered to the low-end, getting cameras in people's hands to get them using Kodak film was their bread and butter, it was very much a "give away the razor, sell the blades" at least in the low-end market.

(and they introduced 620 and 628 film with different spool sizes to try and brand-lock you to Kodak! Today some cameras can be converted, or you can clip down the rim of the spool, or rewind 120 film (in a darkroom/darkbag) onto the 620 spool. It's a little bit smaller spool which can cause problems with film spacing on "automatic" cameras, but, red-window style cameras don't care, or you can use a 620 spool on the takeup.)

In the early days it was "postcard cameras" shooting 122 film (bigger than 120!) that would be contact-printed onto postcards, typically either folding cameras or box cameras (the latter being even simpler and cheaper - brownie launched at one dollar in 1900). Later, this evolved into viewfinder cameras/point-and-shoots.

https://postcardhistory.net/2022/09/the-kodak-model-3a-postc...

https://mymodernmet.com/kodak-brownie-camera/

But if you are contact printing (effectively 1:1 enlargement - the print is the same size as the negative), or enlarging only a small amount onto a 4x6 or 5x7 print, the lens isn't that critical. Meniscus is fine, rapid rectilinear or triplet is good, tessar is premium. Similarly, when you are shooting B+W film, a vague "instant" (usually about 1/100, sometimes 1/60) shutter setting is fine... the exposure latitude will cover you even though you're not perfectly on.

And it was sensational being able to send a picture of your own family through the mail on a postcard, like you were a movie star or something! Very very popular for the time.

And even then there were models that specialized in getting relatively decent quality at minimal cost, like the Argus C3. Definitely a cost-optimized camera but I doubt you could get anything better at the prices it sold at.

Anyway, today we tend to have a survival bias about this - yes, a leica or a rolleiflex or a kodak retina or a contax was quite expensive, not a mass-market thing at all! But 90% of everything is crap, it always has been (it's equally true of PC hardware today, f.ex), and we forget about the Kodak Pony 135s and the crappy box cameras with meniscus lenses and guillotine shutters because they're crap. But those were the mass-market products of their day.

(I'm sure you know this, iirc we've interacted on photo threads before, I just like sharing. ;) But I disagree on the "photography wasn't mass market" bit, box cameras and cheapo bakelite viewfinder stuff has been a thing for a long time and it's easy to forget that with survivor bias.)