Personally that's why I think 'async' in most languages is a farce - it could've never occured to 90s programmers, as back then applications frequently swapped out parts of their program code and state onto the disk - and there's no 'async' to save you from that.

Nowadays disks are fast, but a lot of apps are heavy - your Electron-based webapp is hundreds of megs of binary - there's no saving you from having to load that the same way. In fact most likely your app will have less assets to load than the sum of binaries.