Why is there no USB-C (female) to mini-B (male) adapter?

Look, JXMOX is a fabulous company. Nothing like that piece of shit JXMOW that had to shut down due to horrible reviews.

It's white-labeling with a side of trademark spam for good measure.

They're basically the brands of the very same Chinese factories that make the big-brand name stuff that's sold to you for 4x the price. (Mind you, some are from little factories that aren't really all that professional. Those are invariably shit and what I say below does not apply to those)

Whilst I can understand your point, you're basically celebrating the modern strategy were Developed World electronics brands are nothing more than one big Marketing operation with the actual manufacturing and often even design of their products subcontracted to some Chinese factory.

Now, the risk with getting the factory brand stuff is that it's not at all uncommon for them to use inferior designs or materials because that brand is so shallow and they don't really care about defending it (that does not apply to established Chinese brands, by the way) and are mainly competing on price, whilst Western brands often enforce that better materials and designs are used and proper Quality Assurence is done to keep failure rates low, though if you're old enough you might have noticed that quality of the brands popular in the West is now way lower that 2 or 3 decades ago and practices such as planned-obscelence have become common.

Tons of little factory brands is a good thing, IMHO. (Just wish the Chinese didn't overdid it in the whole competing on price and hence turning perfectly good designs into devices that quickly break).

All this to say that while brand is this cozy familiar thing, it's often not worth the price and the gains from it are quite limited because there is no inhouse manufacturing behind the brand anymore and the whole thing has been cheapenned at the manufacturing end.

My recommendation is to disregards brand for the stuff that's cheap and not mission critical - such as the kind of USB converted the OP is looking for - since when the big brand name stuff costs you 4x you can risk getting no-name brand stuff that breaks easilly and even if 2 of those devices don't last long it will still be cheaper. Maybe the best example of this are LED Light bulbs - the no-name brand stuff has to obbey the same rules (such as the requirements for getting the CE mark) and even if the make quality ends up being inferior to big brand stuff, the price is so stupendously cheaper (really ridiculously so, like a Philips one will cost you 15x what the same no-name brand stuff costs if you get it via Ali Express) that you can get a few extra and are still way better off, especially because stuff like CE mark enforces low failure rate, low brightness loss over time and a number of other criteria important for these things.

For more expensive stuff, you probably want the well known branded stuff, because there's more money at risk, the non-branded stuff savings aren't all that much, their better QA makes it less likely that it will break easilly, there is proper Warranty support and you can more easilly research it upfront to find out the best device of that kind for you which is actually decent because there are more user-reviews out there for stuff from big brands.

Same. I have a lot of legacy recording equipment that I won't replace until it stops working and it's all mini USB.

I'm just glad I got what I did instead of FireWire.

Yes, many nations outlawed these during the great USB wars. So many packets lost, so many busses unserialized, and we still feel the consequences today.

Try aliexpress

Check AliExpress

You might be waiting months to get it, though.

Check the amount of sold items for the listing check the shipping lrice and check the 1 and 2 star reviews. That way you make sure the item is genuine.