

Right, I’m not saying it isn’t simpler in terms of syntax. The point I was making is that the syntax is simpler but in a way that makes it worse because while it’s easier for computers to read, it’s harder for humans.
it was only later discovered that they can be compiled down to native code.
That sounds extremely unlikely. I think you’re misinterpreting this quote (which is fair enough; it’s not very clear):
Steve Russell said, look, why don’t I program this eval … and I said to him, ho, ho, you’re confusing theory with practice, this eval is intended for reading, not for computing. But he went ahead and did it. That is, he compiled the eval in my paper into IBM 704 machine code, fixing bugs, and then advertised this as a Lisp interpreter, which it certainly was. So at that point Lisp had essentially the form that it has today …
As far as I can tell Lisp was always intended to be compiled and executed. That quote is about compiling the eval() function (which was just meant to explain how Lisp is executed) into a binary and using that as an interpreter.
Also I skimmed the paper that is from, and in fact Lisp was intended to be targeted by AI (in the same way that we get AI to write and execute Python to solve problems), which explains a lot. It wasn’t designed for humans to write, so why bother with nice syntax; just have the machine write the AST directly!
(I expect that was only part of the motivation tbf, but still!)

Not necessarily - look at Starlark for example. (I’m also not a huge fan of that but it does demonstrate that you don’t have to have a weird functional language to avoid the issues of side effects.)