People need to understand first and foremost that dogs do not speak English or any human language. Ever. However, they do have a need to express themselves - to tell us, humans, that they want to be left alone, or that they are feeling unwell, fearful, overwhelmed, frightened or in a situation they just aren’t comfortable. It's the only red flag they can put up, a warning.
Yes, they do have a voice, you say, but have to understand they are a nonverbal species, where we're the gabby ones. There are time when a dog needs to tell those around it to back off or that he/she don’t like something so close to it, or is suffering being in a situation which evokes a bad memory, to use a few examples.
This brings us to growling. Teaching your dog not to growl takes away its ability to warn you and anyone else to STAY AWAY, for whatever the reason. You need to respect that. (NEVER EVER YELL AT YOUR DOG FOR GROWLING!)
Example - When I adopted my Australian Shepherd, Berries, years ago, the former owner had done just that - taught her not to growl, how I don’t know. I had no idea and I got bit six times before I realized what Berries was trying to tell me. Eventually, I was able to bring her back to growling, which didn’t happen often as I learned what was causing her distress and trained for them to make her more comfortable. She was a very smart dog and I still miss her, and I’m proud to say, we learned a lot together.
Take your time with your four-legged friend and be patient. Understand that you need to learn WHY your dog is growling, for there can be many reasons. Look at each situation and train accordingly. And if you need help, let me know. We can always to do face time, because having a happy dog is wonderful!