The concrete financials are still dependent on an assumption that someone else will buy a product that the company makes. It seems inescapable that the bedrock of any definition of value is what someone else is willing to pay for something. As an example, you could assume that bitcoin should have zero value, but apply concrete financials to derive a non-zero value of a bitcoin mining company. To get the valuation of anything, you ultimately have to make an assumption about what people will value in the future.