Fibre Upload Speed - why so low compared to download?

[Wurst1]

We've been with Sky Full Fibre 500/Ultrafast Plus for several months, and in terms of reliability and speed it's generally been okay. Our minimum guaranteed download speed is 400mb, and we get around 450mb-500mb most days.

Our upload speed is around 45mb-65mb.

Which leads me to the question - why are Sky's fibre upload speed so much lower than the download speed we get?

I've used residential fibre in other countries where their upload and download speeds are almost idential - 500/450, even 999/950.

Why is this? Is there any way to change it using a router? 

Thanks

[TimmyBGood]

@Wurst1 

Fundamentally because the wholesale broadband providers on the Openreach network in the UK don't offer symmetrical connections at domestic prices to their ISP clients. Changing the router can have no effect because it's inherent to the underlying service: only moving to business provision ('leased line') at a much higher monthly cost gets faster upload.

Altnet ISPs are much more likely to provide symmetrical service on their own private networks.