..and putting a money basket in a farm stand doesn't mean the produce costs money?

And yes, advertisements definitely do cover hard costs like hosting (serving you is not free) and paying for the time/expertise to produce the content.

I don't know how you convinced yourself that digital data is worthless, but it's not and actually costs money to make and serve. Just like everything else you (hopefully) have no problem covering the cost of (you don't just take from farm stands, do you?)