All of the above. Sometimes the system you need to change was written six years ago by an intern from another team that was defragged, in a framework that isn't supported anymore, and everyone keeps piling the tech debt higher.

Some parts of Eng are mind-blowingly incompetent. Google is remarkable not for "hiring the best people" but for how widely the quality varies by org. Some orgs have a reputation for incompetence.

Security and Privacy is a great example. Half the org is fanatical about protecting users, smart, effective, the works...and the other half is fanatical about ticking the right boxes on their forms and putting roadblocks in front of product teams because it makes them look important. Try getting something done when someone from the second group is paying attention to you, and yeah, it'll take nine months to launch a settings page.

Yes, there's bloat, but it's not as simple as "there are too many people so MMM ruins your productivity".