I think of cloud platforms as less complex than managing your own systems. It's trivial to go from zero to functional product on GCP or AWS, and it's honestly not very expensive to get started either. GCP and AWS very clearly subsidize costs for early-stage startups in an effort to lock them in. A tiny startup might have a cloud hosting cost of 3 figures a year until they really take off.

And when your product does take off, scaling is often trivial.