Difference in pipe and file redirection - BASH

Question

Redirection is used to redirect stdout/stdin/stderr! Ex: ls > log.txt.

Pipes are used to give the output of a command as input to another command. Ex: ls | grep file.txt

Why exactly are these two operators doing the same thing?

Why not just write ls > grep to pass the output through, isn't this just a kind of redirection also?

I realize Linux is "Do one thing and do it well", so there has to be more of a logical reason that I'm missing.

Answer 1

You do need a differentiating syntax feature - and using > vs. | will do just fine.

If you used > in both scenarios, how would you know whether

ls > grep

is trying to write to a file named grep or send input to the grep command?

^{grep is perhaps not the best example, as you may then be tempted to disambiguate by the presence of grep's mandatory arguments; however, (optionally) argument-less commands do exist, such as column.
that other guy offers another example in the comments: test may refer to a test output file or to the argument-less invocation of the standard test command.}

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Another way of looking at it:

Your suggestion is essentially to use > as a generic send-output-somewhere operator, irrespective of the type of target (file vs. command).

However, that only shifts the need for disambiguation, and then you have to disambiguate when specifying the target - is it a file to output to or a command to run?

Given that the shell also has an implicit disambiguation feature when it comes to the first token of a simple command - foo [...] only ever invokes a command - differentiating at the level of the operator - > for outputting to files, | for sending to commands - is the sensible choice.