Raw files store only one channel per pixel. A TIFF has been demosaiced and stores 3 channels per pixel. On top of that, most sensible raw formats only store 12

Raw files store only one channel per pixel. A TIFF has been demosaiced and stores 3 channels per pixel. On top of that, most sensible raw formats only store 12 or 14 bits per pixel, instead of 16. And then most are compressed, some losslessly and some lossily (like the infamous Sony format that packs it down to an average of 8 bits per pixel but does exhibit artifacts).