How did ‘concern’ semantically shift to mean ‘commercial enterprise '?

[StackExchange]

No, it's not a "concern" in the sense of "worries". It's a concern in the sense of "commercial enterprise, entity".

PS: From the sense of busyness came the business meaning of “concern” I suppose.

1. How are these 2 senses of concern related? What semantic notions underlie the popular sense of 'worries', with this esoteric sense of 'commercial enterprise'? I need much more detail than these snippety sentences above.

2. Please trace all semantic shifts from Latin concernō (“I mix, sift, or mingle together, as in a sieve”) to this sense of English ‘concern’? How, and why, did concernō shift to ‘concern’ meaning "an establishment for the transaction of business"?

I never heard of this 'obscure meaning where it means "business"'!

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FYI a "concern" is quite old english for an establishment or business of some kind.
[/quote]

3. But why use "concern" when "business”, "corporation", or "enterprise" are more intuitive and understandable?

[Brave]

It's none of your concern/business

[StackExchange]

@Brave, please elaborate?

[Brave]

I'm just not sure that there was a real semantic shift since these two sentences are identical in meaning:

It's none of your concern.
It's none of your business.

In general, a concern and a business are both things you worry about (or concern yourself with or busy yourself with).