My download starts at 98 mb/s then slows to 168 kb/s after 3 seconds when downloading offline games.

Presumably a potato bug crawled into the wires between somewhere around Poland and the USA, causing a fault.

I hope GOG is in the process of going through the servers and games one by one and checking them after the big ouch a while back.

I blame Fallout 4. YMMV.

The Moderators need to consolidate and merge all these threads about the same problem, the extremely slow download speeds, into a single thread.

What moderators ?...

I don't think we have those anymore. Again.

They are likely too busy trying to fix the issue or GOG cannot afford to pay them, because they are paying someone else to fix the issue.

Or GOG are just not responding, so they don't have to lie, hoping we will lay the blame elsewhere.

I downloaded Ghost of a Tale (only 5GB) 4 days ago but it took around... 3 hours? With download at "more than a day" at 1.3 mbps. And in the end it said download failed, but mysteriously it's actually finished.

Not mysterious at all really. Just means that somewhere in the download is corruption. Most downloaders don't endlessly keep trying to overcome errors, they eventually timeout after downloading all they can.

It can be near impossible for GOG to analyze why some (but apparently not all) users in some remote parts of the world have download issues, and where in the internet paths the issue lies.

We get such requests from our paying clients as well sometimes, and usually we can reply only with "we don't see any issues in our network and your server doesn't seem to be under heavy load either, so the issue must be somewhere else on the internet".

I guess all GOG could do was to ask the user to report to which server they are connecting, and then send email to the CDN provider (Fastly?) and ask "hey, you don't happen to have any issues on your server X?", to which Fastly replies "Nope, everything's green and dandy", and GOG is like "Uh, ok, I guess...".

Oops wrong post

As much as Australia might seem remote to some, it isn't really, and I live in the suburbs of a city, not a remote area. I am also not the only one suffering speed issues right now, as some folk in the USA and other parts of the world are suffering too. And neither is my issue the norm with GOG or beyond GOG, as it only occurred recently and coincided with the issues GOG themselves reported a few weeks back ... supposedly fixed now, but clearly not. So in all likelihood it is either a GOG issue or CDN issue and not a route issue, unless that is what was changed by them, which of course then needs to be changed back or rerouted another way.

They should certainly be doing at least that if the fault is not their's.

Since GOG/CDN provider has no access to the user's ISP's routing tables and shit, it is quite limited what they can do.