Interesting - I’d not spotted this (I’m always in the narrower view) but it’d be nice to have the functionality in both modes. Here, though (Kubuntu 21.04, deb install, dark mode), the buttons that appear over messages other than the current one don’t respect the currently selected style - they’re always light, even though I use the Dark theme.
+1 I guess. I find the narrow view more informative because it actually shows sender, title, and excerpt separately, but the lack of delete and archive buttons makes it otherwise less useful.
It is also weird that they don’t show up because in the narrow view email items are actually bigger and have more space for them than in the wide view, because the wide view is trying to stick everything in 1 vertically very short row.