iOS is very good about sandboxing and only letting apps run things while the app is open and focused on. It shows green and orange dots when the camera or mic is being used, and none of my use them without saying so and they only do so when they actually need them. If that is the case, are there any potential privacy issues with it?
As others have said, it’s all about your threat model.
For me, I keep mic and camera off at all times until I need it. Its a slight nuisance, but I’m nearly sure that it covers all the bases.
I could go hardcore and physically disable the mic in my phone, then only use earbuds for my mic. That’s a bit much for me, and maybe my situation is a bit much for you.