Google or Meta, through their data, know exactly who most likely needs your services or products. They know who searches what and who might need what but they won’t let your ad show up on those people's timeline.
Let me tell you why:
Paid Ads is a business. That’s reason enough! They want enough of your money but send your posts to an irrelevant audience. The actual people that might need your service or product won't see your post. Your business actually needs to reach the target market, not just random people..
He’s how they satisfy you to think that your ad campaigns work, yet it dodn’t deliver the intended results:
>In settings they let you define your goal. If you set it as 'getting messages', they make sure to send your post to as many irrelevant people as possible as long as they will click and send a message to you. It doesn’t matter what their intent is, as long as they click and send a massage, your card is debited. Same to setting your goal to engagement. Your ad will be sent to people that engage but never buy. Same to other goals.. Remember that one is never a client until they pay!
Conclusion
The actual ad target would be reaching potential clients, people that actually need the product or service, not just making your socials and website busy but unproductive.