We still learned UML diagrams in school in 2019, though I have to say I haven't used it anywhere in my job

In the case of UML, I think enterprise consulting and tool sales might've already obscured much of the real value of semiformal methods, before a CS curriculum could sour students on it.

With ZIRP growth scheme startups hopefully over, and more of us having to get jobs building systems that work reliably and sustainably, we might gain a new appreciation for system modeling.