A key thing to understand is that post-CD/DVD, you may not be the one who is making the file that the listener gets. The music or video service does that, because the listeners may not all be getting the same format.
If you submit your masters to iTunes, they want the 24/96 master. From the Mastered for iTunes guide:
An ideal master will have 24-bit 96kHz resolution. These files contain more detail from which our encoders can create more accurate encodes.
That is because they use the 24/96 master as a template for all other formats. Right now (early 2016) they ship a 16-bit 44.1kHz AAC to customers, but at some point in the future they will bump that up, using the same 24/96 master of your song, and likely ship multiple formats.
If you’re publishing on Bandcamp, this is from their Uploading guide:
Why the WAV/AIFF/FLAC upload requirement? Why don’t you just accept MP3s? It’s all about maximizing flexibility for you and your fans.
WAV, AIFF and FLAC are high-fidelity (lossless) formats. By starting
with the highest possible quality source, we’re able to convert your
tracks into a bunch of different format and quality combinations …
Can I upload my 24-bit tracks? You bet. Your 24-bit and 16-bit tunes are welcome, and lossless file downloads (FLAC or ALAC) will
always have the same bit-depth as the originals you upload.
So not only does Bandcamp want you to upload a lossless 24-bit file, they can distribute your 24-bit audio to listeners right now.
Other services will also move to this model if they are not there already. YouTube has been doing it for video for years. They will take one 4K video from you and make a bunch of encodes at different sizes and bitrates and give viewers the right one for their situation, based on playback resolution and bandwidth.
So if your recording system can do 24 channels of 24/96 without failing you in some major way, you should definitely record, mix, and master in 24/96, as though no other format existed. Because you can’t know what format the listeners will ultimately get, both today and in the near future. You just need to be concerned with capturing and creating as much quality as possible when you are recording, mixing, and mastering.
If you can’t do 24/96 without reducing your channels too much then fallback to 24-bit 44.1kHz so that at least you aren’t doing sample rate conversion to generate 16-bit 44.1kHz.