I find the "cat foo | .." in the beginning and "| cat > bar" at the end form more regular.
While iterating on a command line, it keeps things uniform, rather than switching between "sort foo" and "tai64nlocal < foo" and "ffmpeg -i foo", by which I mean: different programs take their input in different ways. You can normalize by making each take standard input, and feed the chain with a "cat".
I can understand liking the regularity but in production code or web examples it shouldn't be done because of the overhead. However, your example doesn't make sense.
If sort, tai64nlocal, and ffmpeg are all happy to read stdin so you can do
While iterating on a command line, it keeps things uniform, rather than switching between "sort foo" and "tai64nlocal < foo" and "ffmpeg -i foo", by which I mean: different programs take their input in different ways. You can normalize by making each take standard input, and feed the chain with a "cat".