No issues with Google Music from me, and I've listened all day with most of the major music streaming services on multiple occasions, including Tidal MQA only and their Lossless (HiFi) tracks. Google uses Lame version 3.98 CBR 320, which is mostly audibly transparent for just about all music.
Can't explain why you would get tired, but it doesn't appear that you fully understand the quality level of mp3, and just how transparent it could be. It is far from horrible.
With my current setup, I was able to successfully pass the Phillips Golden Ear Challenge when it was available. So my ears and gear is not really the issue. I was also able to identify a difference in an ABX test between Tidal FLAC and Tidal AAC, and the verifiable results are posted somewhere on Head-Fi, including the test files for anyone to test for themselves. Now I did make my own test files based on a CD rip of the same Tidal song, and I was unable to hear a difference in an ABX between my own FLAC, the Tidal FLAC, and my own mp3 or AAC. So whatever Tidal is doing to their AAC lossy files, it is causing a difference that I am able to detect with some music. Then I extracted the Google Music version of the same song, and again I was unable to hear a difference between the Google file, the Tidal FLAC, my own CD-ripped FLAC, or either my own mp3 or aac file.
In fact, I did test several Google Music files with a FLAC lossless at Red Book or even "HD" (24/96), and I was never able to show a difference with an ABX using Foobar.
Sorry you get fatigued, but I really don't think that well-encoded MP3 is any worse than AAC. There isn't any reliable evidence to suggest otherwise.