jwr parent
I don't have that :-) — what I see when I click the thingamajig on the left side of the URL is a menu with "Hide Distracting Items", "Zoom", "Find" and "Website settings".
For me it’s hidden behind a kebab menu in that thingamajig you described.
Well, either it isn't there in my Safari (macOS 15.7.2) or I can't find it.
I have found "Connection Security Details…" in the "Safari" menu, though. But my point still stands: average users won't see any certificate information without serious effort.
Ah no, i am on iOS 26.