If you’re ok with just having stereo sound or don’t really care if the sound is high quality, then you don’t need one. A soundbar can help boost your TV’s sound, as long as you’re not expecting a huge increase in the quality of that sound. But, if you’re looking for a high-quality surround sound system for a home theater setup, you need to have an AV receiver. They’ll boost the quality and quantity of the sound to give you a more immersive experience. So they’re definitely worth it if that’s what you’re looking for.