Wouldn’t owning their real estate in New York require access to tens of millions of dollars in cash? Where is a bookshop owner going to get that? It sounds more like a practical barrier to doing that rather than a choice thing in their ‘DNA’.

"tens of millions of dollars in cash"

You're replying to someone who wrote "40 years ago." Real estate in New York was cheap, back in the 1970s and early 1980s. I have friends who bought their brownstone in Brooklyn for $200,000, which is now worth $2 million. If you were lucky enough to buy real estate in New York in the early 1980s, it was among the best investments possible.

For awhile I lived in a 4 story building in Brooklyn, just across from the Navy Yard. It had 14 apartments in it. It was owned by a Hasidic Jew, who I got to know pretty well. He told me he bought it in 1982 for $300,000. I'd guess it is now worth $3 or $4 million.

I realize that the national story is different from the New York story, but those bookstores could have bought their buildings, when real estate values crashed, back at the end of the 1960s.

If you invested $300k in the Dow in 1982, it would be worth $8,700,000 today, for reference.

40 years of collecting rent, or alternately deriving utility from living there is a significant part of the return on top of the increase in market price.

Running a business is about cash flow.

Yes, and if you have a landlord then the cash will always end up flowing in their direction.

If you own the building, the cash flows right where you want it. Until then, you're a turtle without a shell.