I heard about a tyrant called Nimrood that challenged Allah and tried to fight the Almighty, but then Allah (SWT) sent a mosquito which killed Nimrood, why doesnt this happen to tyrants that try to challenge the Lord nowadays, i always hear that nations were destroyed for doing evil centuries ago, but there r still nations to this day that r still corrupt and evil, why doesnt Allah (SWT) destroy them just how Nimorood was desttroyed or how Sodom was destroyed, etc etc?
Every tyranny has an end, but if Allah started ending tyrants the moment they start then they won't be exposed and will never exist. It is Allah's discretion how long he keeps something and how long age he gives to it. From the perspective of those who are suffering from it; Allah can protect them from hardships even before start of hard times. But that is not the design of this life. This life is meant for testing of us humans and hardships are part of this life and even in this life hard times and tyrants imposed on us are because of our wrong doings.