Worked for Google for 5 years. Red badges were largely confined to QA testers, physical security, and the kitchen, along with a few UI designers or engineers that didn't want to be employees because they liked the freedom that being a contractor allowed (eg. being able to work for someone else on the side). Basically everyone I interacted with on a daily basis was a FTE. Product area could have something to do with it: I was on a core product (Search), it's possible red badges are more common in peripheral products.
Your comment downplays the number of contractors at Google as if they are rare, but in reality, Google employs ~100k FTEs and ~120k contractors. It's definitely more than just QA testers and kitchen staff.
You may really have just been on a team that doesn't interact often with contractors, but the reality for the broader company is that contracting is a way of life for much more than just Uber.
My understanding is that a lot of those are jobs like street view driver, autonomous vehicle tester, search quality rater, contract recruiter, content moderator, con-ops (help forums & customer support), etc. That's a big portion of the company but not a big portion of core engineering teams. I'd acknowledged the existence of them in my original comment, but this article is specifically about layoffs of software engineers within Uber's core products. I maintain that someone in that position is far more likely to come in contact with other FTEs than with contractors.
I'm not sure about Google, but I know that many companies segregate contractors into other buildings. At one of my previous employers pretty much everyone I interacted with was a full time employee as well, but that was only because contractors largely did not have badge access to the office and worked somewhere else.
