Hey,
to me it sounds like you have wrong / outdated versions of adb & fastboot or are using wrong /outdated adb drivers.
Please uninstall your adb & fastboot and the Google USB driver you mentioned.
Then go ahead and download & install universal adb drivers from here:
https://adb.clockworkmod.com/ aswell as tiny adb & fastboot from here:
https://xdaforums.com/t/tool-windows-tiny-adb-fastboot-august-2021.3944288/
Afterwards try again to install this ROM and make sure to follow the instruction steps closely.
I am getting 10 hours of SoT using the microG ROM on my personal device.
Please note that this can vary depending on your battery condition and the apps you installed.