Why does FireFox not continue its Firefox OS open source project based on KaiOS’s successful experience?

KaiOS is a closed source fork of Firefox OS that is embedded with a lot of ads API.

As a low-end mobile phone system for poor people, however, it is definitely not a good/ethical system.

Why Firefox doesn’t re-initiate its Firefox OS project for those USD20 smart feature phones?

Why a open source Firefox decided to help a closed source fork to upgrade B2G engine?

An open source system can motivate more developers to join and develop apps for poor people.

And the web apps developed for KaiOS can be simply transferred and adapted to new Firefox OS.

The sources used to build the core of KaiOS are free - that’s the Boot2Gecko source - but unfortunately all the user-interface bits are closed source AFAIK. It is possible to build a Firefox OS derivative on top of those and frankly I’d be glad if there was some momentum to. I’ve been pushing for using that technology in a more widespread way and hopefully it will eventually find its way into another fully free project eventually.

For now unfortunately there are no efforts in this direction within Mozilla.