Google Tag Manager can be down without affecting websites uptime and as a visitor I can block them. I do block them, by the way. So, it's quite central, but at

Google Tag Manager can be down without affecting websites uptime and as a visitor I can block them. I do block them, by the way. So, it's quite central, but at least not really a point of failure. AWS and Cloudflare, on the contrary… (and also Google products like fonts.googleapi.com, or probably anything under googleapi.com)