Omar Zenhom explains why Google Ads fail: your search terms, ad copy, and landing page need to match. SaaS businesses especially lose conversions when they send all traffic to one generic page instead of creating targeted landing pages for each ad.
A lot of the times the problem is in Google Ads, the problem is just the confusion on the landing page. You've got to always think about it in the customer journey. So if they're searching for a certain term, they're seeing your ad copy, and then they go into a landing page which isn't highly relevant back to that first initial search term, you just lose them straight away. So with Google Ads, one of the things that I do see, especially for a software as a service industry, is that you need a whole collection of different landing pages which speak specifically to the ad and speak specifically to the user.