I completely agree, there's no reason any engine can't have VVT. I believe that famous northern european supercar guy, I think "Keurig" or something like this is is name - he took an old beater car 4 cylinder engine and superpowered it with some pneumatic / AI controlled valves - I think it's called "FreeValve" or something like this.

As for two strokes being "less efficient", efficiency is in the eye of the beholder. We see on the recent key bridge collapse lore that indeed these mammoth cargo ships run two stroke engines, in this case, two stroke turbodiesels which formerly were the mainstay engine of american trucking. The humble weed eater or chainsaw also tends to use two-stroke - why? because they're far more efficient, almost twice as efficient, in power-per-pound of engine i.e. in applications where lightweight is needed. An added benefit is mechanical simplicity. The double-power notion follows from the name, these engines give power every two strokes versus every four strokes. Two strokes are also really interesting in that exhaust manifold geometry interacts with the engine stroke with pressure waves, look at any two-stroke dirtbike and some will have these goofy-appearing exhaust manifolds for this reason. Granted the major challenge of two-strokes is dirty/pollution and being oil-burning by their nature.