Is there any benefit of executing "| xargs" without any arguments?

I came across scripts where | xargs is executed without any arguments. I started removing such occurrences because scripts just work without them but wanted to verify that I'm not missing something. Perhaps xargs defaults to sanitising some characters, etc.

... | cut -d: -f2- | xargs

Is there any point of having the | xargs above? Thanks in advance.

Without any arguments xargs will combine all lines in the output into a single line, and will remove extra spaces:

$ echo $'a   b\nb'
a   b
b

$ echo $'a   b\nb' | xargs
a b b

Note that this will only work if the input of xargs is smaller than the maximum size of the command buffer. See example below:

$ seq 100 | xargs | wc -l
1
$ seq 1000000 | xargs | wc -l
53

As per @user000001's answer, it's useful to "cleanup" whitespaces (including newlines) from stdin, into nicely one-line single-space separated values.

An interesting use-case arises when you need to "join" these values in a shell CLI (by join I mean adding a separator between all values), for example, you want to sum the size of all files in your current directory (similar to du somehow):

$ stat *|sed -n 's/^size//p'|xargs
5589886 11669381 4096 1743 2467 4096 22447289 1784723 27472 203 4096 525 4096 4096 4511158 268533 131068 150307 75658 12288 4096 4096 102762 4096 4096 4096 7296 5782043 4096 4096 779 14855386 895468 4096 4096 227

# replace each single whitespace from `xargs` by `+` and pipe it to `bc`
# to get the sum of all numbers
$ stat *|sed -n 's/^size//p'|xargs|sed 's/ /+/g'|bc -l
68374006

This construct might seem useful to flatten the input with echo (which is called by xargs by default) but it has a few border cases depending on the content of stdin AND the implementation of echo:

1. it might trim leading/trailing/duplicate white spaces:

   printf '%s\n' '  a' 'b  b' 'c  ' | xargs
   

   a b b c
   

2. as @user000001 explained, when the input is too long, echo will be called multiple times, giving you multiple lines of output

3. xargs has it's own escaping rules; for example the presence of single/double quotes in the input might break the command:

   printf '%s\n' "I'll be there" | xargs
   

   xargs: unmatched single quote
   

4. echo has undefined behaviors; the output of

   printf '%s\n' 'a\\nb' | xargs    # \\ means \ for xargs
   

   could be

   a\nb
   

   as well as

   a
   b
   

ASIDE

For a sure-fire method of flattening the input, I would replace:

... | cut -d: -f2- | xargs

with:

... | cut -d: -f2- | paste -sd ' ' | sed 's/ \+/ /g; s/^ //; s/ $//'

^{note: the sed is for trimming leading/trailing/duplicate white spaces}