The steam store used to burn CPU on Windows until at least up to 2017 (on fresh install it would a strong PC stutter on startup). It tries to kill your DNS reso

The steam store used to burn CPU on Windows until at least up to 2017 (on fresh install it would a strong PC stutter on startup). It tries to kill your DNS resolver on linux when downloading games (~20 requests/sec when) which actually decreases your download speed by a bunch. This bug has been documented in 2014, and was still present last time I had to debug this a year or two ago.