I found GitHub's old "how many visits to this status page have there been recently" graph on their status page to be an absurdly neat solution to this.

Requires zero insight into other infrastructure, absolutely minimal automation, but immediately gives you an idea whether it's down for just you or everybody. Sadly now deceased.

I like that https://discordstatus.com/ shows the API response times as well. There's times where Discord will seem to have issues, and those correlate very well with increased API response times usually.

Reddit Status used to show API response times way back in the day as well when I used to use the site, but they've really watered it down since then. Everything that goes there needs to be manually put in now AFAIK. Not to mention that one of the few sections is for "ads.reddit.com", classic.

https://steamstat.us still has this - while not official it's pretty nice.