ELI5: Internet was supposed to be free(Monetarily). But, how?

So I´m having this argument in the office.

Internet in it´s cradle was supposed to be a network with free access to it. That makes sense IMO for development environments (Military or universities) since the organization that wants to access the network would take care of all the infrastructure.

But what for the regular users?

Did people spect to have access at home, I guess through an ISP, without paying to it for all the maintenance of the network? Another way of viewing it is that people would be requesting the telephone companies to use their lanes for free, (it is not like the internet usage would flood the network rendering useless Correct me if Im wrong here)