I actually have exactly this, paired with ntfy. I was thinking more like badges: "was up during AWS outage in 2025" etc.

Uptime Kuma already has some automatically generated badges[1], but not for specific events. Your could manually built your own custom ones based on the same framework[2] though.

[1] https://github.com/louislam/uptime-kuma/wiki/Badge

[2] https://shields.io/

Where would you put it? :) (I have one on the oracle free tier)

I just selfhost it, but that has the disadvantage that it also went out during my ISP's and Cloudflares outage. ;)