This also led to popularity of bigger reselling setups (I don't miss installing cpanel...) and services like Dreamhost.
MySQL in this way gained a virtuous cycle completely unrelated to Google. Hell, most people I know, who dealt with LAMP space for years, never knew Google had anything to do with MySQL (most people that knew about it were... Lispers. Because of who built the first version of Google Ads)
Even Mac OS X Server shipped with MySQL and PHP because of that, in 2001.
Replication was something you did when you got succesful enough to have it, or were a MSP providing it at premium to others.
Digg.com also had a really influential technical team - hearing about how they did things set a lot of baseline defaults for a lot of people.
Essentially, start at 2000-2001 and more and more people going into running websites for all kinds of reasons (forums, blogs, webshops, etc. often hosted on low end offerings)