Earlier quoted context omitted.
Such as?
Affinity Designer, Photo, and Publisher to name a few, from the same company. [0] Then there are many games, which by their nature require native performance, and of course have to present the same frontend. :) [0] https://affinity.serif.com
These are powerful pieces of software which massively benefit from native code doing processor/GPU intensive tasks. Totally different use-case.
Slack is literally just a fancy messaging app.