Is DC 5V and 2A dangerous to me?
200mA is lethal (actually much much less is lethal) and can kill, but only it if gets inside you. For it to get into you, it needs enough voltage behind it to push into you. If there is enough voltage to push a lethal level of current into you, and enough of that current is actually available to push then it is lethal.

Think about a bullet. It's a little piece of lead and is lethal right? Well, it's only lethal if it gets inside you. For it to get inside you, something has to be behind it to push it hard enough to get inside you. So a lead ball the size of your first is even more lethal right? After all, it's even more of the deadly stuff a bullet is made of. Again, only if it gets inside you so something has to be pushing it hard enough to get inside you.

On the opposite end is static electricity which actually does have a high enough voltage to push those lethal level of currents inside you...but static electricity doesn't have enough power behind it to produce that current so it doesn't kill you. It's like shooting a grain of sand at you at high speed. It has the push, but it's not pushing "enough stuff into you" to do any damage

Then there is something like a lightning bolt which has both the voltages to push those currents into you AND the power to produce those currents, and those can definitely kill.