You are describing the www of the 90s. Ok, we didn't host at home but basically you "built your own website". There were no "big businesses based on ad revenue and traffic funnels".
Of course (compared to now) it sucked. Discoverability was hard. Quality was (let's be generous) erratic. There was no interaction (no comments, chat et al - thats what email and news (nntp) were for.
If you look at the big businesses based on ad revenue (Google, YouTube, facebook) they evolved out of that landscape specifically to solve problems. Those problems remain regardless of where the sites are hosted, so moving the hosts won't affect them.
Of course (compared to now) it sucked. Discoverability was hard. Quality was (let's be generous) erratic. There was no interaction (no comments, chat et al - thats what email and news (nntp) were for.
If you look at the big businesses based on ad revenue (Google, YouTube, facebook) they evolved out of that landscape specifically to solve problems. Those problems remain regardless of where the sites are hosted, so moving the hosts won't affect them.