The thing is, some of you think of a nuclear war when someone asks you about WW3, but it doesn't have to be a nuclear conflict. In a nuclear war we'll probably face extinction, but in a conventional one you can expect normal trading to continue. You will still have Internet access, be able to watch the news on TV, just like people in WW2 had newspapers and radios. The media kept functioning throughout the war.
In Russia’s war against Ukraine, which is now in its third year, Putin and his entourage have repeatedly threatened Ukraine and the whole world with the use of nuclear weapons. One by one, the conditions were set that if the Ukrainian Armed Forces attacked the annexed Crimea, the territory of Russia itself, Moscow, then nuclear weapons would be used. But the Ukrainians are now attacking both the Crimea peninsula they captured and almost the entire territory of Russia, including Moscow.
If they attack you and try to kill you with conventional weapons, then it practically doesn’t matter if they also blackmail you with the use of nuclear weapons. If you die, then it makes no difference from what weapon, so Ukraine practically does not react to nuclear blackmail and continues to defend itself by all available means. In addition, any use of nuclear weapons will boomerang on the territory of Russia itself and this cannot be ignored. Even the use of small tactical nuclear weapons will mean that it will be impossible to live normally in this territory for decades and centuries. And then why do the occupiers need such conquered territory? In 2022, the Russians invaded the Chernobyl zone of Ukraine from Belarus and even dug in there. After some time, they were all taken to Belarus with signs of radiation sickness. They say that every single one of them has already died. But almost forty years have passed since the accident at the Chernobyl nuclear power plant.
Therefore, not everything is so simple. A major war involving many nuclear states does not really mean that it will be nuclear. But at the same time, it only takes a few idiots with access to the nuclear button to threaten the existence of all humanity. After all, if even one nuclear explosion occurs, after that there will no longer be any deterrent to the use of other nuclear weapons.