I’ll introduce the story that esbuild does not support transpiling to ES5.

Background: I wanted to transpile to ES5

I was looking for a tool that could easily transpile to ES5. I investigated whether esbuild could achieve this, but it seems it doesn’t support transpiling to ES5.

esbuild does not transpile to ES5

esbuild - An extremely fast JavaScript bundler

ESBuild doesn't transpile your code down to ES5.

Source: ESBuild doesn’t transpile your code down to ES5. If you’re using any ES6 feature… | Hacker News

That’s all from the Gemba about wanting to transpile to ES5 with esbuild.