The webcam on your Mac is not nearly as good as the camera on your iPhone. The video might be blurry and colors are sometimes washed out. It doesn't keep you well-lit. But if you've purchased an iPhone in the last few years, you have a very good camera right in your pocket.
An app named Camo lets you use your iPhone as your Mac's webcam. It's super easy to set up. It even integrates with popular video chat services you're probably already using for work or school, like Zoom, Google Meet, and Microsoft Teams, and Slack in your web browser.
Camo is free to use, though you can pay for a premium version that starts at $4.99 a month and gets rid of a small Camo logo that appears during videos, works on two computers, and removes a watermark. But you'll still see an upgrade if you don't.
Just as a quick example, here's what I look like on the webcam of the newest MacBook Air: