Google Ads and Meta Ads spend your budget chasing whatever you tell them is a conversion. If a page view is being counted as an enquiry, they optimise for page views.
It's common for enquiry forms and booking tools to sit on a different domain, or to send without loading a new page, so the enquiry never reaches GA4 or the ad platforms at all. CRO changes are measured the same way, so the numbers have to be right before anything is changed.
Once they are, every month I find the point where visitors drop out, make a change, and measure whether it worked.