Ask HN: Anybody still into ES5 + traditional Javascript dev workflow? Why?

Client Javascript development has drastically changed in the last 5-7 years. ES6+ Standards, module bundlers, Managing dependencies with NPM, Typescript & such modern elements in the toolchain is becoming the de-facto.

Are there any companies, projects/products, indie devs out there still sticking to plain old JS development without the modern tools?

Are there any reasons to not switch to the modern workflow?