Some of us still work on embedded systems with real-time guarantees.

Believe it or not, at least some of those modern practices (unit testing, CI, etc) do make a big (positive) difference there.

The depressing part is that these "modern practices" were essentially invented in the 1960s by defense and aerospace projects like the NTDS, LLRV/LLTV, and Digital Fly-by-Wire to produce safety-critical software, and the rest of the software industry simply ignored them until the last couple of decades.