Interesting question, since the web used to exist and work just fine before online advertising. I'm not saying that we should go back in time, but claiming that ads are a requirement for the web to exist is a slight overstatement.
>>adamby+(OP)
> Interesting question, since the web used to exist and work just fine before online advertising.
For what definition of "work"? There were static informational pages and....not much else. Content that requires upkeep requires revenue requires either ads or access fees, usually.