I love using the manual mode of my camera. It can be challenging to adjust all the settings in the moment but I enjoy that challenge and enjoy getting better at it. Some days though, I don't want to put in so much effort. Using Shutter Priority Mode allows me to let the camera help out.
When I'm taking photos of November Project, like I've talked about in this previous post, using Shutter Priority Mode allows me to simply lock in the shutter speed at 1/500s or 1/400s and the camera will automatically keep the Aperture as low as possible since the amount of light is still low. I can also turn on Auto ISO. The Sony cameras allow you to select a range for Auto ISO too which is very useful. In the summer, when the light is good, I'll keep the range at ISO 100 to 400. In the winter, I'll use ISO 100 to 6400. If your camera doesn't have the range ability with Auto ISO, you could simple use Auto ISO and be fine. Remember, a grainy photo is better than no photo.
ISO 100 - F4.5 - 1/500s
The Sony A7 iii camera is ISO invariant which means that the camera is adding in artificial brightness after ISO 800. It is similar to how Lightroom adds brightness. So the theory is that if your camera and Lightroom are both adding brightness via some algorithm, your computer is going to be better at doing it than your camera. So take photos at maximum ISO 800 and lighten them up in Lightroom.
So far this has proven to be true but it still makes me nervous in the moment, especially since I can't check my photos for composition while taking them or even after since they're so dark. You can do some simple Google searching to see if your camera is ISO invariant. For my Sony pals, it seems you're in luck with the A7 iii and the A7R iii. Not so much with the A6000 but perhaps with the A6300, A6400, and A6500.
Using Manual Mode can be fun but isn't always necessary. Shutter Priority Mode can be a welcomed break for those days you'd rather focus on other things. This is one myth that I hear about professional photographers. We don't always use Manual Mode just because it's the professional thing to do. We use our cameras as our tool like any artist would. Knowing and mastering all the capabilities of our tools and when or how to use those capabilities is what makes us professional.