The best environment for recording audio is one that allows you to record clean audio. Clean audio is audio that is free from distracting sounds and harsh frequencies. To learn more about clean audio, read our knowledge base post: What does clean audio mean?
In most situations that means recording audio in a dedicated recording studio. However, for the majority of projects, that location is not suitable as you're unlikely to be filming in a recording studio.
For corporate or narrative projects, your environment is usually dictated by the location you are filming in. As such, as a sound recordist it is your responsibility to ensure you make the environment suitable for audio recording.
This means mitigating distracting sounds such as conversations and traffic noise by using sound blankets, correctly positioning the microphone, and communicating that you need silence on set.