Cash doesn't really exist in the payments stack for an online business. Credit card chargebacks can roll in months after a compute instance is closed down and companies like Google have little recourse here.
I know AWS does, or did, take wire transfers for payment.
Those are much harder to claw back, particularly if you have a signed agreement from the customer saying "We want to pre-pay for $50k in compute resources. We understand that once the pre-paid amount is used, it cannot be refunded."
I'm sure GCP and any other legitimate cloud provider could also take wire transfers for sizable payments, without issue.
"Just take cash" isn't an option.