My guess would be that most people calling in to a call on Zoom from their phone are leaving it on speakerphone and not holding it up to their ear/mouth like yo

My guess would be that most people calling in to a call on Zoom from their phone are leaving it on speakerphone and not holding it up to their ear/mouth like you would with an old land-line phone. Opening up an omni-directional mic that has to pick up someone from 1-2 feet away from their mouth is a lot different than an old-school phone that you pick up and hold an inch away from your lips. You're not paying Apple $1000 for a microphone on a stick when you buy an iPhone, you're buying a computer that has a tiny microphone that works well enough for most normal phone calls to your doctor or whichever. If you care about audio quality as a foremost feature, you do what business people have been doing for years and buy a wireless headset/in-ear with a directional mic that's built for comfort and tuned to pick up audio in the exact distance range of your ear to your mouth.