Is there any way to get updates except manual github releases?

Also it pays to keep mozilla alive.It helps in defending anti-competitive lawsuits.

Sad to say there are only two engines available for the open web.(Not considering Safari as that is only available on apple)

Vivaldi has a better vision.In android, I use stripped-out version of Firefox i.e.fennec and mull. I do have open-source fork of chromium, Bromite just-in case I need it.

what are you using now?

But donating your money can not make firefox independent.It will only make firefox more revenue.

Google wants to keep mozilla afloat to stay out of anti-competitive allegations.