Ask HN: What is Web3? How the business model works?

What happens when I the company create a databse (let's say facebook) and Developer A create more compelling application that facebook company?

1.Where is the controlling part. 2. what facebook internal advantage/motivation to create and hire more engineers and give dopemine to more people?

Saying company facebook own coin which has no value what does this even mean?

Explain to me.