As a result, the music file that left Qobuz servers 5,000 miles away is the same music file that arrives at your streamer’s network interface
I’m just pointing out a variety of explanations for why files can sound different - not including end user hardware and real world losses.
I had a friend at Netflix in the early 2010s developing their pipeline, and he told me about ways they would bounce streams around different countries in Micronesia to experiment discreetly with customers without your local IP’s knowing, so they can subdivide what people within a given are receive. (Don’t remember the whole story).
So in conclusion, there are many opportunities to how the streamers can sound different and they are intensely competitive with each other, and we may never know the full details. There are people whose job it is to alter, throttle, and reroute streams all over the world so everyone is frictionless - with trillion dollar markets caps and billions of users, its in no way "a simple direct stream for everyone". Delivering non-stop content is more important to their shareholders than retaining fidelity to the original - one quarter of laggy streams can result in a $50billion market cap haircut if users cancel, so expect shenanigans and expect things constantly changing.
I recommend always support your artists by purchasing their digital masters and playing them locally :)

