There are a lot of posts going on, but let me just post this link to a specific file of the bun zig code base so you can have your own impression:
https://github.com/oven-sh/bun/blob/bun-v1.1.42/src/bundler/...
My take is they vibe coded too close to the sun
I'm left with a good impression.
Lot's of comments on the whys and historic context.
Backed by tons of tests.
Yes the file could use some modularisation and splitting into smaller parts but maybe the gains were weighted and judged against.
That file is a great example of KISS.