Avoiding this route to sail directly to Northern Europe may also be why a Greek explorer from Marseille, Pytheas [1], gave us one of the first, if not the first, direct accounts of the British Isles.
From at least the 16th century BC, amber was moved from Northern Europe to the Mediterranean area.[2][3] The breast ornament of the Egyptian pharaoh Tutankhamen (c. 1333–1324 BC) contains large Baltic amber beads.
Not that I have any knowledge of ancient trade routes, but to me having a trade route from Britain towards the northeast instead of southeast feels weird.
In any case, I don't think it's much more of a detour though, especially if we assume that it wasn't a specific journey, but a chain of multiple cultures interacting with each other. It doesn't seem implausible to me that tin went from Britain to Scandinavia then down the Amber Road, but I'm not a historian.
As in: Nobody decided "let's start a trade route from Egypt to Scandinavia!".
Far more likely, people traded with their neighbors, and market forces led to goods step by step traveling to where they were most valued.
Probably without Egyptians and Scandinavians ever having a clue the other group existed.
But even that would have been possible, if anyone had enough knowledge of enough prices for common trade goods at enough of the ports along the way. One trip would make the owner, captain, and crew rich enough for it to be worth the risk.