Everything has a downside, and Google Ads are no exception. First and foremost, it’s not necessarily easy to learn how to find the right keywords. You could easily waste a lot of money and time while you’re learning with very little to show for it. If you don’t choose the right keywords, your ad might be seen by the wrong people… or never seen at all.
You also need to learn about negative keywords, how bidding works, how to create impactful ads and landing pages, and then be willing and able to invest the time to monitor your ads and tweak them as needed. It’s not a set it and forget it process.