Probably because (AFAIK) Electron currently requires you to have each platform to build that platform's release. At least that's what I thought I saw last time

Probably because (AFAIK) Electron currently requires you to have each platform to build that platform's release. At least that's what I thought I saw last time I checked? Also there are subtle differences in platforms which means you actually need to test. Simple examples are menu differences (no app menu on windows). Forking external command line program differences. Application data differences etc. (maybe someone will make the electron cross platform CI tester?)