In the case of a circuit breaker, at least in the countries I lived they weren't available without the local agency approvals (which could bring some level of scrutiny). The case for caveat emptor is if the person actually equipped their entire house with breakers bought from an international marketplace, bypassing the local regulations. In this case, it is not "victim blaming" but idiocy and no amount of rules can prevent that.
Unfortunately that does not address the case where a person hires someone else to do the work, as there are too many curious people acting as handymen or general contractors. In this case, you would have to resort to recommendations from friends and neighbours.
A similar case can be made for the fuses, but it is obviously much harder to enforce (size, low cost, relative brands, etc). In an ideal world, the marketplace store should not have possession of a counterfeit fuse in the first place, but unfortunately that is not possible at all.
You're right, the actual situation is complicated. I.e. It is not Black and White, but some funny shade of grey. It also, varies widely, depending on what items you are talking about.
So, for me to say "Victim Blaming", earlier in the thread, is NOT that clear case.
An example, could be someone who is doing lots of DIY electronics repair/upgrading, to their home in the UK. They have counted that they need 5 mains sockets, 5 light switches, 5 circuit breakers, 5 reels of wire, 5 bulb holders, and 5 junction boxes (obviously I'm making this example up!).
So this member of the public, who wants to save lots of money (compared to paying for a proper electrician to do all the work), has the big shopping list of items, to buy.
They soon discover, it would cost (made up figures), hundreds of pounds to buy from their local DIY stores (but would have been safety approved types). So, they go to the local markets and perhaps ebay.
Because they discover they can get the entire list for a fraction of the cost.
I'm NOT 100% sure. But I suspect these hypothetical members of the public, DON'T necessarily (some might know), that those cheap markets and cheap sellers on ebay. Might be selling shoddy/unsafe, unapproved items.
So they may just end up buying them, without realising how potentially dangerous they can be.
That's why EVERYTHING available for UK buyers (and really the Western world), should be safety approved items. They shouldn't be able to just pop along to their local market (which IS covered by UK regulations, and is at least partially checked, from time to time), or buy unsafe items on ebay.
But in practice they can. So I don't have any easy/quick/realistic answers. Except to say, the range of potentially unsafe items for sale on ebay (foreign sellers), has got to huge numbers.
Also, some items seem to cause disputes, as to if they are unsafe or safe, in practice. A good example that comes to mind is those 'live', directly mains connect/live, internally heated, shower head, things.
Mains chargers and powerful rechargeable batteries, can be especially dangerous (electric shock (charger) and fire risks, both items). Yet members of the general public (in my experience), DON'T appreciate the potential dangers of such items.
tl;dr
This is obviously turning out to be a big and complicated subject area. Any change, will probably have to be made by governments round the world, rather than by us, engineers and other professions/hobbyists.
Or we would need to decide what needs to be fixed, and then campaign hard for the solution to be implemented.