I assure you 19th Century newspapers had advertisements.
For example:
https://chroniclingamerica.loc.gov/lccn/sn86072192/1897-08-0...
And an 18th Century newspaper with advertisements:
https://chroniclingamerica.loc.gov/lccn/sn83021183/1777-03-0...
How far back do you go to find newspapers with no advertisements?