> Code should be holistically understood and it's your job as a technical leader to know how the parts move
That's true when we design something. Once the design is done, and is broken, we have to tear it back apart to understand WHAT is broken. That's when blame is useful.
I love using git blame. I love it even more when it comes back with something I made, because then I get to learn. When something I thought was safe turned out to break something, that's an invaluable chance to understand the system better.
That being said, I've totally used the blame output to end a series of excuses from a junior about how "his code was definitely right, but everything else was garbage" because I really do not care. If it worked before, but doesn't work now, that's a problem. Part of the modern process of "fail fast" is also to build up taste about which parts of a working system are spooky.
I find that some people take the "blameless" culture too far, and use it as an excuse not to reflect on outcomes. They just ruffle the code whenever there's a big, and don't think critically about why that bug appeared. What that tells us about the system we're making.