Google and Samsung now provide updates for 7 years, and Fairphone provides updates for 8 years.
From what I can tell, Apple doesn’t promise a set number of years for updates. The iPhone x got about 5 years of updates before support was dropped, but Apple will occasionally give security updates to older devices if they’re severe enough.
I’ve been using this website to monitor federation status between Sopuli and lemmy.world:
https://grafana.lem.rocks/d/bdid38k9p0t1cf/federation-health-single-instance-overview?orgId=1&var-instance=sopuli.xyz&var-remote_instance=lemmy.world&from=now-12h&to=now
You can set it to any two Lemmy instances, and it offers a lot of good info, especially when one instance is falling behind.