Sourcemaps have the drawback that you actually need to generate them first. Sometimes, getting all of the tooling together is teedious. And about the size: if

Sourcemaps have the drawback that you actually need to generate them first. Sometimes, getting all of the tooling together is teedious. And about the size: if the JS file is cached properly, downloading 1.5mb once doesn't seem like a huge issue, especially for something like Slack where only desktops use the web client (most mobiles probably download the Slack app). I don't know if this was the case here though.