Are acoustic treatments really necessary?

When a room is untreated there can be certain frequencies that cause havoc. This makes some form of acoustic treatment, even as simple as monitor stands highly recommended for mixing.

Is there a difference between acoustic treatment and soundproofing?

Acoustic treatment is about taming certain frequencies and reverberation in a room. Soundproofing on the other hand, is more focused on preventing sound from escaping a room.

Is there a workaround for recording in a bad-sounding room with no acoustic treatment?

A bad sounding room is a bad sounding room, unless you use acoustic treatment. However, during the mixing process, you can use notch EQ to tame problem frequencies. Specialist software like Izotope RX is also great at ‘fixing’ audio. This can only go so far though, so we recommend some form of acoustic treatment if possible. This will provide better results from the get-go and save you a lot of time and frustration.