I think most major value of stream style is that we can solve callback hell problem by them. https://techblog.yahoo.co.jp/javascript/nodejs/callback-to-promise/

Callback を撲滅せよ

こんにちは。言語サポート（Node.js）チームの伊藤（@koh110）です。Node.js v10 も10月にLTSとなり async/await によるフロー制御は当たり前のように利用されるようになってきました。JavaScript...

9:16 AM

↑This article is written about Promise, async await in JavaScript. They are not stream but can avoid callback hell. Same worth is in streams.

9:20 AM

Streams are more high level abstraction than Promises. They can encapsulate about start of asynchronous operations. A one of good example is .retry operator in ReactiveX.

9:22 AM

If you use stream more agressive, you can get power of immutable programming and safety. Everythins is a stream meme says about this style. https://www.google.com/search?q=everything+is+stream&client=safari&rls=en&sxsrf=ACYBGNSrL5EOg_7a__un_phY7QRiR-SjEw:1570526439303&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjippn0qozlAhXvGKYKHWI2DNYQ_AUIESgB&biw=1430&bih=779 (edited)