A big difference here is the sheer scale of investment. In 1985, the internet was running on the dreams of a few. The sheer depth of investment in "AI" currently is hard to fathom, and being injected into everything regardless of what customers want.
While ARPANET itself reportedly cost somewhere between 10 - 20 million USD, which is relatively cheap, the precursor research that allowed the internet to take off - which is directed more at general computing and advanced computer networks, the telecommunications investments - cost many billions of dollars, it was mostly public money is the biggest difference.
That said, private companies are pumping alot of money into this space, but technological progress is a peaks and valley situation. I imagine most of the money will ultimately move the needle very little following things of dubious hindsight value
That's because the tech industry has more money than god and nothing better to do with it.
Microsoft alone has half a trillion dollars in assets, and Apple/Google/Meta/Amazon are in similar financial positions. Spending a few tens of billions on datacenters is, as crazy as it sounds, nothing to them.