Yes, @fredrik222 does not understand streaming.
So the answer to the original question, not that I think I understand it. I didn't know that Qobuz sold songs to download, but if they do, there is likely an improvement in the quality of the digital data, depending on your system. Downloaded files are not time sensitive so they use error checking, like banking, defense industry, or other critical functions, to ensure that the downloaded file is an EXACT copy of the original file.
Streaming cannot do this. Streaming must keep up with the music so streaming always has error management tool that interpolates for any missing bit and moves on. Now if you have a high end streamer and great internet service to it, there may be very few missing bits. OTOH, if you are streaming wirelessly, there are a lot of missing bits and a downloaded song will have much better digital representation.
Jerry