What percentage of the chip cost is the wage cost? This might be relevant for a 90uM process, but I think at 4nm, the wages are a minuscule part of the production costs.
> The material is just silicon.
No, a lot of chemicals are required as well.
Yes, Obviously there's a lot that goes on in this process, more then "just" silicon. But if you want a summary, then cost expertise and knowhow, eclipses actual process. In a sense it is just "silicon" when measured relative to the ability and knowledge required to transform that material.