This is an engineering argument that's disguised as a business argument. In reality a monolith had way less overhead when starting a new product or business and makes a lot more sense than sinking resources into something that isn't even needed at the time. Not to mention that from an engineering standpoint you can't even know for certain which components need to be broken out onto a microservice without the evidence of traffic.

Following your logic to its ultimate conclusion, you may as well also over-hire on staff, get a super expensive office, crazy benefits packages, etc. Why not? You dont need that stuff if you think your business will eventually fail.