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>a couple of things that JavaScript got so incredibly correct: . . . Lexical scope natively without syntax or conventions

What language of the last 28 years doesn't "natively" lexically scope its variables?

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Not Javascript. If I forget a var or let, it's global.

Strict mode throws an error on implied globals. Use of modules forces strict mode.

And that's all "extra" syntax.

strict mode is the default in everything now and had been for many many years.

It isn't the default for a browser "<script>" tag.

It's the default for <script type="module">, which you should use anyway for anything serious.

JavaScript is different in that it use the function as the lexical scope rather then the angel brackets. This forces you to think about the code as functions, rather then blocks. And in turn helps you think of the code in three dimensions where time is one dimension, making it easier to understand code that runs asynchronously.

Because people coming from other languages find this confusing the let (and const) keyword was specified (ES6/2015) for block/angel-bracket lexical scope. Whereas var is function scoped.

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