I'd rank it well above all of your list except the wheel and the plough. It's just that we haven't seen the full effect of the Internet yet. There are likely innovations yet to come that will reshape society on a greater level than any of the others. We haven't had an information-age war the way that WW1 was an industrial-age war, for example. Large areas around drones, satellites, smart clothing, augmented reality, crypto-finance, etc. remaining untapped.

I'd rank the Internet (and software, in general) up with agriculture and mass-production as a fundamental technology for society. These both ushered in totally new eras for humanity (the agricultural and industrial revolutions, respectively) and new forms of wealth (land and capital, respectively). Similarly, the Internet ushers in the information revolution, where data becomes a fourth fundamental factor of production.

do you think if the internet had somehow existed prior to these inventions, their creation would have been hastened?

No, the inventors would become influencers selling CBD oil.