While true and might be easy to read in the example context of a b c I'd imagine having the && separator in real world conditions to be far more readable and clear for vast majority if people

Pipe looks far too much like a 1 or lowercase ell.

I actually think the variadic logical and is more readable, and wish more languages had it. As long as all the arguments are lined up vertically, you can think of it as a sequence of tests for true that exits at the first failure. It's more obvious with the variadic operator. Contrived comparison:

  if (a != null && x != 0 && a.use_it(x))
  {
      ...
  }


  (if (and (not (null a))
           (/= 0 x)
           (use-it a x))
      ...)

Most, and possibly all languages I've used day to day do not have prefix operators like that.

Prefix operators considered harmful for readability.

... at the cost of having parentheses around every subexpression.

I hate Excel for this very reason.