Cost and risk.

Edge networking services can be expensive and Cloudflare offers a free tier which is decent. Additionally, I’m sure down detector has a method of making money, but I sure don’t pay them. I can’t imagine I’m the weird one. So they are almost certainly operating on a tight budget.

It’s fresh in our minds today, but these big providers are way more reliable than not. It makes sense to use them because they are generally not down.

It just doesn’t make sense to do anything different. I doubt they change even after this outage. I certainly wouldn’t.