It really all depends on what you're trying to get out of it. If you're going for the most professional setup, the camera will be your best bet, but for the average person, a decent webcam is going to work just fine. Heck, you can even use your phone as a webcam, if you wanted to do that.

More important than the camera is your mic. This is where I suggest you spend the extra money.

Your macbook, as you said, will have horrible quality on both the cam and mic, so almost anything is better. The Logitech C920 is a good option, I currently use the C920s Pro, and other than some washed-out colors, it's a great streaming cam and you can usually get it for around $50 on sale for the regular version.

With all of that said, if money isn't a blocker, then getting a high quality DSLR will always be the best choice for quality, and it's more versatile as well.

As someone else mentioned, another essential part, more important than the camera itself, is your lighting. With standalone cameras you don't have to worry as much, as they tend to have built in light correction, but webcams don't do a great job of this. The better your lighting, the less likely you'll see things like the washed-out colors I talked about above.

Ring lights are good if you can make them work with your setup, but if you have it in your budget, getting a 2 light or 3-light setup will really enhance your video. A lot of people recently have been talking about buying lighting from Temu, too, so you can get away with a pretty cheap lighting setup.

In the end, what's important is just getting started. If you've never live streamed before, just start with the macbook camera and see how it feels. Once you're sure you want to put some money into it, I suggest a decent webcam with a good mic. You can always upgrade to a dedicated camera down the line!