Again, why is the scary second half of that sentence an absolute certainty or bad? There's no law requiring use of innerHTML, and it's been easy to beat React on raw performance in many cases (to their credit, that's been getting harder but that's always a challenge for a general purpose library) — and in most cases none of that matters because you're not triggering updates fast enough to care. Ease of use and all of the other concerns are far more important for most people.

Similarly, if people are building reusable components it's not clear why using different virtualdom libraries or not using one at all is a problem. Doesn't sound software engineering practice recommend a well-defined public interface rather than deeply interconnecting them like that? Besides, this is the web: what are the odds that you wouldn't quickly hit a problem where component X depends on v1.2.3 but component Y requires v2.3.4?