If you want to use a terminal that is actually open source and doesn't have telemetry, much less only available via signing in with GitHub, use Alacritty, also written in Rust and cross platform. https://github.com/alacritty/alacritty
I use Konsole. It's written in I-dont-know-and-dont-give-a-shit-why-is-that-even-relevant. It's free, does not spy on me, comes by default with Kubuntu and has great themes out of the box (including the Solarized themes).
Same. But boy to people really like tools "written in Rust".