he's not demented, he's just arrogant and egomaniac, he doesn't care. he thinks he knows better than anyone. and yes he doesn't care that he made the nazi salute, he wanted to provoke.
i'm not convinced that he is entirely incompetent. Maybe to european standards, but he managed to get elected as president. Twice. And the second time has the backing of not only putin but also of the american tech oligarchs. How is that incompetence?
It is. 5090 is roughly 25% faster for 25% more power and 25% more power. So it's just an overlocked 4090. And this after two years of developing. Zero efficiency increase.