Fastboot command only works in one mode, and adb in another mode. And if adb doesn’t do anything it could also be a temporary problem on the computer.
This is the /e/os page for your g30 : https://doc.e.foundation/devices/caprip/community Can you get into recovery mode ?
Okay, being able to go into the recovery mode is a good thing I would say. Did you search on XDA forum ? For example : https://xdaforums.com/t/hard-brick-moto-g30.4397117 and https://xdaforums.com/t/bricked-motorola-g30.4716793 could be useful to read ?