Vaguely related amusing bit of trivia: the word for smith or blacksmith is one of the most common names about everywhere: Smith (England), Schmidt (Germany), Smit/Smet (Belgium, Netherlands), Fabre/Favre/Lefèvre/Lefèbvre (France), Ferrari/Fabri (Italy), Ferrero/Herrero (Spain), Ferreiro (Portugal), Kowalski (Poland), Haddad (Morocco), Demirci (Turkey), Demirdjian (Armenia), Gof/Goff/Le Goff (Brittany, Wales), Gowan/Gowen/Gow/Gough (Scotland), Kuznitz/Kuznetz/Kuznetzov (Russia), etc.
Also lots of religious names, at least in Spain but probably in many romance countries, since last names were derived from the father's name: Pedro (given) => Perez (son of Pedro), Alvaro => Alvarez, etc.
To add to this bit of trivia. In Sweden this was never a thing where your job became your surname. If you go to a cemetery you'll sometimes see the occupation on the gravestone though, especially on older graves and if it was a more higher class job.
Admittedly it seems less common, but... there certainly are some Smeds in Sweden (and the rest of Scandinavia). The names are not ALL sons/sens and geographic features... https://forebears.io/surnames/smed
Less common is an understatement. Less than 300 people have Smed(h) as their surname in Sweden. We also don't know if they originated in Sweden or if this was a Swedification of a foreign surname.
A pice of trivia: in Polish it should also be Kowal (Koval). Land owners were taking the names of the places they owned, so if you owned a village called, called Paris, you took the name Pariski (adjective). This created a culture of adding a ski to your name. There was even a book of peasants that weren't upper class, but took that name.
For some reason the version in Portuguese is Ferreira (the feminine form), not Ferreiro. No idea what the reason is. I somehow doubt that medieval Portugal was exceptionally gender-progressive.
It's the feminine because it refers to the family, and "família" is feminine. e.g. "João Ferreira" would be "John, [of the] blacksmith [family]". That's also the reason a few surnames include de/da/do (of/of the).
A bit of googling gives me the explanation of "ferreira" being an old word for "iron mine", which to be honest is coherent with modern portuguese forms like "pedreira", toponymics ("ferreira" is a common place name), and the way names come about (João da Ferreira would own or work in the iron mine, or just come from one of the villages where there was an iron mine).
Armenian is Darbinian/Tarpinian (Demirjian is the Turkish-Armenian hybrid form). There's also related Nalbandian (farrier / horseshoe blacksmith).
BTW, the theory I've heard is that this surname prevails due to survivorship bias, in countries that were constantly at war and the male population was being decimated, the smiths had to stay back home manufacturing weapons (same logic applies for "miller" and "tailor" and "mayor", all very common last names in large parts of Europe).
Not in Romania (the Hungarian name Kovacs is #90, and the Romanian names Feraru/Fieraru are not in top 100) But Popa (priest) is #1, Popescu (son of a priest) is #2, Cojocaru (furrier) is #46 and Szabo (tailor in Hungarian) is #62
