I STILL DON'T THINK COMPANIES SERVE YOU ADS BASED ON SPYING THROUGH YOUR MICROPHONE

Summary from the TLDR newsletter

Many people are convinced that companies are targeting ads to them by listening through their phone's microphones. For this to be true, companies would have to record audio snippets, transmit them back to their servers for additional processing, and then feed that data into a system that forwards it to advertising partners. This is far-fetched, especially for companies like Apple, which has a brand and reputation as a privacy-first company and spends large amounts on product design and engineering to prevent apps from doing exactly this kind of thing. The more likely scenario is that the quality of targeting is high and that people just aren't that different from each other.