I think GPs point is that they haven't gone from zero to a working solution, they've gone from zero to N% towards a working solution and then slowed down everyone else. Maybe for the most trivial programs they can actually reach a solution.
You can't write a program without knowing that x is a string or a number, your only choice is whether you document that or not.
Yes you can, you handle every case equally. You don’t even need the reflection mechanisms to be visible to the user with a good type system. A good type system participates in codegen.
for a really simple example: languages which allow narrowing a numeric to a float, but also let you interpolate either into a string without knowing which you have.
A statically typed Console.log in JS/TS would be an unnecessary annoyance.
You can't write a program without knowing that x is a string or a number, your only choice is whether you document that or not.