I agree. I think the author leans too much on the supposed incompatibility of OO style and ECS style, which they explain only by linking to the Wikipedia page

I agree. I think the author leans too much on the supposed incompatibility of OO style and ECS style, which they explain only by linking to the Wikipedia page for object-relational impedance mismatch. I've worked in many systems that satisfy the author's description of ECS in their treatment of the central domain objects, and they were all built in OO languages and were thoroughly OO in the rest of the codebase. I think the author was on the right track in recognizing OO as "a set of mechanics we can cherry pick," but I really don't follow how they think an embrace of ECS style would force programmers to abandon most or all OO mechanics.