I am curious why you consider AWS as centralized. Doesn't it offer a service like any other company? If you want to register a website domain, you need to use something like Google Domains or Godaddy. If you need storage, then you need to have a data center which costs a lot and even big companies outsource these services. A company needs internet connection, so they use the services of telecom companies. They also need electricity, so unless they have a fully solar/off grid setup, they will take electricity from the grid. You also mentioned mobile OS like Apple and Google, so does Web3 need to develop their own OS?

If you want a fully decentralized setup, are you saying they need to setup all these things to not be reliant on another company? But even then, won't the Web3 apps still be reliant on those Web3 companies that set these new infrastructures up?