The confusion, I suspect, is that consumer rights and manufacturer warrsnty are very different things. You always have consumer rights if you are a consumer (i.e. not a business buyer) ajd you might have a manufscturer warranty.
Consumer rights are always enforceable against the business you bought the goods from. This is usually the retailer, unless ypu bought direct from a manufacturer. The extent of those rights, both in what you are and aren't entitled to, are defined by UK law, though that UK law is somewhat defined by EU regulations. If relying on stztutory rights, in your case, it'd be Scsn, as the retailer, you deal with.
Manufacturer warranties are rmuch less regulated, and they aren't obliged to offer anything. If they do, then grnerally you csn enforce it in the courts if need be BUT what they offer, what they exclude, how long they offer it for and the T&C's are more or less what they say they are (in thrir warranty T&Cs).
Where it gets extra confusing is that sometimes, retailers operate as a kind-of agent for manufacturer warranty claims. This is far from uncommon where the manufacturer us not UK-based, and too small to hsve a UK operation. In which case, someone like Sczn might well collect cards up, srnd them back to MSI ina batch, and pass on whatever MSI offer to you. In that case, they're simply acting as a midfle-man, perhaps to save you having to ship the card back internationslly.
To be clear, provided you are a consumer, you MIGHT (and in this case do) have a warranty claim, but ALWAYS have your condumer rights.
Which route you rely on is up to you. But it's worth noting that manufacturer warranty rights are often more generous thsn your statutory consumer rights, and you might well do better, and very likely faster, by going the warranty route.
To give an idea of the variation, I have a kitchen device with a 20-year motor warranty. Consumer righrs top out at 6 or 7 yesrs.
On the other hand, I use a clothes retailer with a 60-day "for any reason" warranty. Cigar burns? Covered. Dog chewed it? Covered.
But if I were to rely on my consumer rights on those clothes I might have several years (whatever "reasonable time" is) but ONLY if the goods were faulty, and the faulr was "inherent" at time of purchzse, such as fsulty design, faulty components or materials, or faulty manufacture. But cigars or dog damage? No chance.
What responsibility Scan have depends kn what you asked of them - facilitate a warranty claim, or your consuner rights.