The seed from this generation either doesn’t grow true when planted the next year, or will be sterile.
Given the right additional growing inputs — fertilizer, herbicides and pesticides – Hybrids can achieve earlier harvest, greater uniformity or greater yields than non-hybrid seed. But, they probably will need the herbicides and pesticides because they haven’t been bred for resistance.
The farmer has to weigh the benefit of an improved crop versus the cost of fertilizers, herbicide, etc, plus the cost of having the buy the seed each year.
The parents used in the initial cross are generally kept as a trade secret by the company that made the Hybrid.