Is this at least partly due to higher resolution / larger displays? Better quality displays with higher resolution sources will make a difference between out-of-focus and in-focus more apparent.
Maybe, but crazy shallow DoF goes back at least to Kubrick famously shooting parts of Barry Lyndon at f0.7.
Barry Lyndon was shot with an f/0.7 lens because Kubrick wanted period-correct lighting: candlelight, which required a super fast lens with the film used. To my knowledge he wasn’t going for shallow DoF.
Be that as it may, the DoF is unavoidable unless every shot is insanely tight.
You are correct. This wonderful article taken from American Cinematographer goes over this very topic in great detail: