Streaming service reduces dynamic range?

My family has Amazon Music Unlimited, and I decided to listen to a track I have downloaded just for comparison. Then another. Then another.

Across several albums of different genres and different eras, I found Amazon Music to have notably worse dynamic range than stuff I downloaded from Bandcamp, ripped from CDs etc. If I match midrange volume between a download and stream of the same song of the (supposedly) same master, I can clearly hear Amazon having “flatter” dynamics.

I tried searching if Amazon dynamically compresses music or whatever, but I can’t find really find anything. I don’t really understand loudness normalization either, so I generally would appreciate any pointers why a song can sound so differently as a file or a stream.