If every company stopped advertising then google and facebook and twitter will disappear. Are all these companies pure waste? How do you fund a replacement for them? Should these services be provided by governments?
In other words, most users could easily afford it.
And yes, here is the current problem, the mindset of the people. Not willing to pay for services and rather get it for "free" and accept manipulation and time waste. On the other hand, where services are adfree avaiable, like netflix, users indeed do pay. So I am positive that it is about to change.
One company that does exactly the same things? No.
Companies that do part of what Google does? Absolutely, duckduckgo for search, countless email services to replace gmail, openstreetmaps to replace gmaps, the list goes on.
I don't see the downside.