Here are the pricing models that the leading cloud providers follow:
AWS is done on Per-Hour basis
Azure pricing model is known as Consumption offers, which is a pay per use model (or maybe a subscription model for a period of 6 months, etc.)
Google Cloud Platform provides billing on a Per-Second basis
GCP is the most cost-effective/cheap cloud provider compared to other cloud service providers.
You can also save more as the Billing for AWS is done on a Per-Hour basis, Microsoft Azure uses a pay per use model, whereas Google Cloud Platform provides billing on a Per-Second basis.
Moreover, Google Offers additional discounts for Long-Term usage and there are no Upfront Costs too.