Great ad, weak page = wasted budget. The landing page is where the promise of the ad must be kept, instantly.
The headline on the page must repeat the promise of the ad. If the ad said '30% off sneakers', the page can't open with a generic homepage.
Headline, hero image, button text — change one, measure, keep the winner. Small lifts compound into big revenue.
Bottom line: send ads to purpose-built pages, not the homepage, and let the page finish what the ad started.