Not disagreeing but this assumes Silicon Valley budgets for startups. The story may be different if you're not funded yet and in discovery mode or if you're bootstrapping.
Does it? Just taking one example "managed" stack: AWS Amplify + Lambda + S3 + DynamoDB. You can get pretty far using the free tier for the first two and using the second two sparingly. If you're spending any more than $20 per month on that stack, then you probably have a significant number of users and traction already.