We're in a different way. Just like with Moses, if only sharing the news about righteous living and serving I AM was enough to turn Pharaoh, no sign gifts would have been needed. But Yahweh needed to prove it, the new way.
In this 'now' time frame, there is no way that sharing the gospel will be enough with just words.
Yahweh has to accelerate the turning with plagues, signs, wonders, and major power shiftings. The power must succeed world-level demons on the earth. It's time for the sign gifts from old to come forward in fullness. My power is surely great; nothing compares to it. Will they believe you? It doesn't matter.