Maybe the hardware on the Google Home Mini isn’t meant to play sounds at high volume well, but when users turn it up loud, they should at least expect it to work.
That said, there have been multiple reports on Reddit and at least one thread on the Google Home Help Forum have been talking about the smart speaker crashing when it plays any more than a few seconds of music at maximum volume. This has happened on multiple units and on multiple songs with the native power cable. One customer even found the issue on an exchanged unit from Best Buy.
Google is now urging users to report this issue through the Google Home app’s feedback page with the keyword “GHT3 – Google Home Mini reboot at high volume.”