Lisp's limited syntax allows everyone to create their own "language" and that's arguably worse than the fixed set of statements that exist in other languages. I'd even argue that Lisp is inhuman because it's brutal compared to natural languages.
This is probably why neither language is more than an intellectual curiosity. COBOL, Fortran and BASIC have also all "stood the test of time".
Not really. Definitely not compared to C# or Java. Smalltalk simply has more system-level code accessible to the user.
I've worked with Java environments that tried to replicate the visual programming features of Smalltalk. They were about 10X the size of a modern Smalltalk distribution (Squak or Pharo), had at least 100 times slower startup time and you still needed an external IDE to get anything "serious" done with them.
If you want to see simplicity that stood the test of time, look at Smalltalk or Lisp.