[1] Could lower bitrates sound better?
[1a] What if the extra information in higher bitrate files causes the headphone driver to interfere with other frequencies? Imagine a hearing headphones reproduce a song, then again the same song but with a 25 kHz tone played the whole time. I'd imagine the reproduction without the tone would be more accurate if you ignore the extra tone.
[2] Also is the missing information even important? Does it degrade the sound like pops on a record? I'd imagine it would depend on the recording.
1. That's not an easy question to answer because exactly how the lower bitrates are achieved varies between different codecs (LAME, Fraunhofer, etc.), depends on how low the bitrate, the settings applied and even the version of the codec. For example, by the time we get to 128kbps and lower, pretty much all the different codecs will discard everything above about 16kHz or lower (as far as I'm aware), but this might not be the case at 192kpbs and might vary with VBR or ABR.
1a. Yes, that is a potential issue. IMD (Inter-Modulation Distortion) is quite common and typically occurs when a driver (or other device) responds non-linearly to very high or ultrasonic frequencies by producing spurious tones (within the audible frequency range). Lower bitrate MP3's would reduce that possibility and even lossless 16/44.1 would eliminate the specific example you've given (as all freqs above 22kHz are removed).
So, in answer to your question; "Yes lower bitrates could sound better" but requires a specific set of circumstances, for example: A lossless recording that contains significant very high/ultrasonic content, a reproduction chain that produces audible IMD in response to that content and an MP3 encoding/bitrate that removes those freqs but doesn't otherwise affect perceived sound quality. This set of circumstances is certainly possible and does occur but I don't know if it's common.
2. The whole point of perceptual lossy codecs (such as MP3, AAC, etc.) is that the missing information is NOT at all important to our perception, it can't be perceived/heard. However, at very low bitrates then there's no choice but to start discarding information that can/could be perceived BUT, it all depends on what we are encoding, the complexity of the music or sound. In those circumstances where data compression artefacts are audible, they don't sound like pops on a record, they typically sound like: Pre-echoes, a metallic ringing, warbling, bird chirps and/or hiss but there are some others.
[1] So if people generally can't hear the difference between Flac and 320kbps why would anyone pay for Tidal over Spotify? Peace of mind?
[2] Also the amount of reviews you get from the big audio sites that talk about how much better Tidal is than Spotify in terms of audio quality baffles me
1. It's not that people "generally" can't hear the difference, they can't EVER hear the difference! The only exceptions I'm aware of is a very small number of recordings and if it's been encoded to 320 a long time ago or with an old MP3 encoder (15 years or so). The only valid reasons I can think of for someone preferring one service over another are: Price, user interface options/functionality and choice of available recordings.
2. It baffles everyone, with the exception of those mislead by marketing into believing that more data always means more/better (audible) sound quality.
G