Comment by convolvatron

you can very reasonably do welding in your garage. aside from a welder (as little as $150 for a barely-usable mig), all you need is an angle grinder to cut and finish the welds. commercially you can get a mid-range mig and a couple more smallish tools and you can start selling custom fencework and mounting brackets and such.

blacksmithing you need a forge, which immediately takes up more space and is somewhat more likely to start a fire. an anvil, and tongs, and hammers. its also a lot more physically demanding, even if you use a power hammer.

your #2 and #3 are pretty key. most importantly most fabrication jobs are much happier to get quick work with reasonable precision using stock shapes. once you start talking about real free-form hot shaping you're immediately going up at least 10x in price/time. welded table base - $500. handcrafted wrought table base - $10,000.

really its that metalwork is mostly functional (fences, stairs, railings, walkways, enclosures, stainless for commercial kitchens, pipefitting, etc). its very difficult to stay in business as a actual craftsman making well-designed objects. architectural metal is probably the easiest in (wall coverings, nice looking railing and stairs, lamps, and other decorative elements). and there its still dominated by fabrication processes (machining and welding of stock shapes), although nicer materials like bronze start to have their place.

edit: you know I left this thinking I was missing something and I realized what it is. welding you make shapes out of like-shapes. like making drawings in figma. I don't think a lot of people have what it takes to learn to be a really good freehand artist. and even if you have the skill, being able to design those kind of organic arbitrary shapes so that they are emotive and attractive is another step up. do you want a piece of art which is a direct expression of the concept held by the artist? or do you want a 3x5' 32" inch high workbench for 1/20 the cost?