Comment by pmontra

Apple make money from the App Store and from selling their hardware, so why should they want to invest on something that let people install software bypassing the App Store or that works on other platforms?

Alphabet make money from ads, so they want web pages, apps on Android and Chrome everywhere.

Mozilla make money from Google.

Microsoft make money from software licenses and subscriptions and from cloud services. They might be interested in cross platform installation.

At the moment what we have is PWA and WASM and icons on the desktop.