Gotta hate screwfix, as If there is a company which will abuse their controll ower manufacturers its kingfisher (owners of Screwfix/B&Q), wether its pushing manufacturers to lower standard to lower Price, when the manufacturer is at a quality low enough to be beeten by chinese then offering chinese version cheaper under screwfixes own brand and when it goes bancrupt lifting chinese items brands price above the originals... (though this is more known as a tescos approach in Europe), wether its the kingfishers habit of bringing cheaper (lower quality) Chinese version of the products (rather then better Europe made version) and when company protests abandoning the brand all together (No more Siemens Thermostats).
Then its a case of taking better makes to china and having them "nearly" copied, but lot cheaper (Those LAP sockets might be sh*t but front used to look suspiciously like click sockets ant their best salles) and then putting their chinese imitations in searches in front of originals while making it harder to focus on a proper (UK/ EU made) originals,
Such as in case of flomastas JG imitations (I know its plumbing) , which when you search, and try to filter by brand, the UKs no1 sold brand wont get displayed as an option untill you chose "more options".
then there are tons of their own brands (could believe that half of all the brands their sell, but did not check) often making them sound german to trick customer.
With the buying power, they can get cable directly from china/turkey so their costs would be lower then that of smaller retailers, but outside price will be more based of what they can charge, rather then cost...
And no, most quality brands just cant manufacture in quality under that kind of pressure, so many of the best brands like Click, Wera, Heller, Bahco, Hagger, Scame, Hilty just aren't there. For quality you have to go either to smaller retailers or online
Can't say I'm a fan of big box shifters like Screwfix, but there are quite a few inaccuracies in your post.
For cable, the top 10 search results on their site are Prysmian products.
197 results for Wera.
82 results for Bahco products, not that I'd consider their tools a 'best brand' these days.
Hilti aren't widely available from any retailer and, other than buying directly from Hilti, the greatest selection of their products can be found on ebay.
Scame a top brand? A widely stocked brand due to their pricing perhaps, and not the worst, but certainly not a top brand. in terms of quality.
The bottom line is very simple - manufacturers can decide who they sell to and many won't sell to companies that don't suit their business model or that want unrealistic prices. Similarly consumers can decide where to buy and many will avoid outlets like Screwfix.
What's good about Screwfix? Well I can think of a few occasions when they pulled me out of a hole on a Sunday afternoon.
Let's compare them to a well known, large electrical wholesaler who are known for poor stocks, poor quality products and eye watering prices...
Toolstation sell a large number of Einhell tools. Designed in Germany, but made in China.
Many other brands assemble goods in Europe and label them as 'made' in a European country, but manufacture of component parts takes place in China.
I can think of local wholesalers where customers are treated as though they're an inconvenience. I can think of products stocked by Screwfix that can be obtained anywhere else locally.
Do I like Screwfix? No.
Do I frequent Screwfix? No.
Do they provide an invaluable service, which can not be fulfilled by other local retailers. At times they do.
You pays your money and takes your choice.