They have something similar in Aus called the Capital Gains Tax and it is something that is inherrently political, unfortunately you can't uncouple the government from as they provide the public service that maintain and collect taxes. Honestly the public service should be answerable to parliament, not government.
Not to mention CGT been tweaked to ineffectiveness by previous governments by excluding assets from its calculations, notably housing, which has skewed CGT away from its original purpose and it's now more of a stick to whack at industries that aren't cozy with the current government.
FirefoxOS was also exclusively targeting the touchscreen market, which by that point was already totally saturated. Their partner deals weren't the best either, and they really launched their product before it was ready which sullied their image quite a bit.
KaiOS had the benefit of hindsight to see where Mozilla fell over, put in mitigations, and then shift focus to non-touchscreen devices to lower costs even further.
A lot of their stack is still open source under the MPLv2, however there are rumours that Google is 'encouraging' KaiOS to shift their rendering engine over to Blink. Whether this happens or not remains to be seen.
Actually, there's not been much change from the original fork of FirefoxOS besides the UI changes to be better for non-touch devices.
GerdaOS (LineageOS for KaiOS) allows people to import and run FirefoxOS packages without modification, though many apps will need some changes to allow it to work without a touchscreen.
The unofficial rumour mill says that with the extra investment from Google, KaiOS will probably shift to Chrome(ium) at some point in the future, but that's just a rumour and remains to be seen.