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It would depend on how you want your audio. Its totally possible to use your phone as a cam. There are several apps to use that work great. You can even use an app called scrcpy if you're on Android.
Some of the newer phones have screen sharing builtin and a third party app isn't even needed.
You can also record on your phone then import it to pc and edit it there.
There is also an Android app called Vlogit that works awesome to even edit and render your videos right on your phone.
If you look in my videos on 3Speak. Every video I did where I was in the truck or out walking around was done on my OnePlus6T using Vlogit app.

I shoot almost everything with my phone. The best camera is the one you have with you

Yeah, I've used my phone as a webcam before. They actually work really well in that capacity. Many of the action cams can also be used as web cams from what I understand. There are a lot of options for web cams.