Yes, indeed. This is exactly the sneaky thing about the cloud. It seems so "simple". Now try doing that for multiple multi-thousand person orgs with competing

Yes, indeed. This is exactly the sneaky thing about the cloud. It seems so "simple". Now try doing that for multiple multi-thousand person orgs with competing processes, architectures, product cycles, etc. You'll find very quickly that costs spiral out of control in a very unpredictable and irreversible way. Self-hosting is something a company has much tighter control of the costs for. Most of those costs are known up front as capex purchases and predictable opex expenditures. They tend to seem expensive compared to the PoC S3 demo you just did, but often aren't compared to the actual realized expenses after migrating.