Our clients often ask for ‘high resolution’ files, this can mean both a higher samplerate than 44.1KHz and/or a greater wordlength (bits) than 16. In our experience people are quite confident around samplerates but misconceptions about wordlength/bits seems more common. Even though 24bit (or higher) may be preferable in some situations we still recommend using 16 bits (and a 44.1KHz samplerate) as format for distribution online. We will continue to do that until there’s a new global standard for online distribution, if there ever going to be one. The reason being that when the files leave the mastering house, all control of the material will be gone. Who knows what dodgy dithers and SRC the different distribution services uses, some may be good, others will sound like crap. By delivering the format that most online platforms use and the format that 90% of the consumers will end up with, you (hopefully) avoid unnecessary conversions between both wordlength/bits and samplerates.
Ian Shepherd recently released the video below that easily shows what a lower number of bits actually means, it’s probably not what you expected:

The truth about bit-depth and digital audio resolution

And, if you want to dive deeper into bit depth and digital audio, plow through this video where Monty Montgomery describes the phenomenon of dither, bits and sampling frequency:

D/A and A/D | Digital Show and Tell (Monty Montgomery @ xiph.org)