I think your opinion lacks perspective. The entire strategic arsenal on each side is no longer 25,000 nukes, but 1550 strategic weapons.
And keep in mind we tested close to 1000 weapons before the nuclear test ban treaty, as did the Soviets. The world didn’t end.
Yeah, the planet didn’t suffer a nuclear winter because we didn’t detonate thousands of nukes at the same time, these detonations were spaced out over the course of 15 to 20 years. It is my understanding that more than 30 detonations simultaneously (of a certain yield) will kick enough sediment into the atmosphere to cause a nuclear winter.