This is a big question! Google my business, or its new name Google Business Profile, is a collaborative tool. Just because you’ve filled in your listing in a certain way doesn’t mean that 6 months later it will be identical. Indeed, customers may have modified your opening hours or your services… in short, all kinds of parameters.
So, yes, Google my business is a reliable tool, but you need to keep an eye on it over time, update it and maintain it to make sure it’s displayed correctly.
Also, be careful: some competitors have fun modifying your listings! To do this, you need to control your listing and your Google account, and be alerted to any changes you make. That’s all I explain in the method.