I'm not a front end expert but, I'm wondering, did anything really change since 2013 that renders the virtual DOM unnecessary? Or was it always unnecessary and people just eventually figured that out?
That hasn't changed in the past decade, and it's not going to change in the next decade either because the DOM has to make certain API guarantees that simply can't be optimized away. It'd take a significant change in how the DOM API works to even get close to achieve performance parity with a virtual DOM. (Like being able to tell the DOM to completely defer layout until you tell it that it's okay to continue.)
It's simply much more reliably performant to have all your DOM touching be done in a single batch during a virtual DOM diff resolution than it is to touch it and update it piecemeal as your application's components all mutate their own elements on their own schedules.