postmarketOS and the people porting Linux to phones
Panfrost devs
Nouveau/NVK
Yuzu (to get better Intel Arc support on Linux)
Libraries I use in OpenRGB
I already donate to one of the libraries I use on GitHub sponsors, also the box86 developer and a few others. I am donating to the UVTools developer as it was cheaper than paying for the shitty proprietary software subscription for my resin printer. I've donated to pmOS in the past as well as Debian and Arch.
Yes but it does have it's downsides, for example it can consume more battery and more computational power to do the same tasks of a native app or it's not compatible with every Android app out there.