I've been using a fork of Thunderbird called Betterbird (https://www.betterbird.eu/) on Linux, mostly because I want to be able to minimize it to a systray icon. I know there are extensions like systray-x and birdtray, but I was having issues with these on Wayland. I wonder if this new version of Thunderbird finally added systray support on Linux/Wayland.
That's... not a bad thing, though? Terry was an extremely competent engineer and programmer who designed his software to be as user-friendly, well-documented, and performant as possible.
I have conversed with Jörg, and he is blunt and fair in a good way (code itself is emotionless, after all). And, of course, he is highly competent. I have also conversed with several Mozilla teams, including Thunderbird, and the experiences were universally horrible, as in they lacked core competency. Naturally, YMMV.