If you're referring to ["The TypeScript Tax"](https://medium.com/javascript-scene/the-typescript-tax-132ff4cb175b https://medium.com/javascript-scene/the-typesc

If you're referring to ["The TypeScript Tax"](https://medium.com/javascript-scene/the-typescript-tax-132ff4cb175b https://medium.com/javascript-scene/the-typescript-tax-132ff...), Eric never said it was useless. "Many developers love using it, and there are many aspects of the TypeScript developer experience I genuinely love." There's a whole section called "What I Love About TypeScript" and he even uses it in some of his open-source projects. What he actually says is that there is a cost to using TypeScript (an obvious fact). And most JavaScript developers use [object concatenation](https://medium.com/javascript-scene/the-hidden-treasures-of-object-composition-60cd89480381 https://medium.com/javascript-scene/the-hidden-treasures-of-...) all the time, especially with Redux. He's right - every JavaScript developer should know what it is and how to use it, even if they don't recognize it by the word "concatenation".