Depending on the application, the performance of the Arc A770 is between a 3060 and a 3070.
The main reasons for the fluctuating performance are the drivers and the DX version (more information on this can be found in various forums, videos, etc.).
The card is mainly made of plastic.
Teardown ARC A770 (GamersNexus):
https://www.youtube.com/watchComparison video performance (Arc A770 / 3060 / 6600XT)
https://www.youtube.com/watch