Is there any reason to move away from Bugzilla? Afaik the reason why they’re not using GitLab issues it’s missing some features they need, which Bugzilla has. Also afaict the language thing is more of a choice than anything. Qt already has excellent Python support, but having everything written in C++ and QML makes things easier. But yes, they definitely could use more money and more paid developers. KDE could really use more manpower.
And yeah, a ton of devs would much rather be working on open source software, but if it’s not directly profitable it’s not gonna generate a lot of jobs. You need a lot of donations just to hire one developer full time. There’s always going to be a lot more jobs in closed source software than in open source.