I agree 100% with what you said, and yes, my thinking there was based on the present day situation. Yes, it will change dramatically with post-peak society. Yes, doing your own mass production works. We do that at any opportunity at present. (My background is in high speed automation for auto manufacturing.)
The trick is to apply the correct approach at the correct opportunity. Slow, painstaking handcrafting won't compete head-to-head with mass production NOW, but it WILL pay when the world begins to operate diferently. I think it is all important to position for both situations. Being nimble about how you do things is the great advantage of the small operation, as contrasted to mass production that is well-nigh impossible to change direction quickly, sort of like an aircraft carrier, compared to a person walking. If we master both sorts of skillsets, and apply them appropriately, we can win every time.
I guess I sounded too negative in the first post, which was not my intent at all. I think you hit an important point with small income streams. An example of that which makes us a few bucks is prowling the junkyard for old tools, such as shovels, axes, sledgehammers, picks, etc., with broken or missing handles. I have a process for rejuvenating these, since there are wood handles available to us as seconds from a local handle factory. First, remove all the old handles, and rivets, doing them a batch of them all at once, to save time. Derust them all with a wire brush on a right angle grinder, and paint them all, hung on wire hooks to dry. Collect handles to suit, and spend a morning installing about 20 of them. The finished tools are stacked in a corner of the shop tagged for sale, at about half of new price, and sell fairly quickly.
Gardening tools done this way have been VERY popular this year! I've known people who specialized in refurbing bicycles and others who did used lawn mowers, and made decent money at it. Even if it is only a single item to sell , like the old farmers' adage, "have something to sell every week". It works. Just because our primary business is welding and machining does not mean we should not make our slack times productive with such things. A winter of salvaging things to sell has paid us well in spring when the outdoor season begins.
Local fix-it guy..