Earlier quoted context omitted.
Because the US requires the same nonsense from EU citizens. Requiring it from theirs creates an incentive to dropping it.
No, it does not create an incentive for the US to drop ESTA. If they dropped it, that would create an asymmetry where where US citizens traveling to Europe are treated worse than Europeans traveling to the US. Hardly any American politician would want that. Introducing this nonsense in the EU means that it will be really hard for either side to drop it, since realistically both sides would have to negotiate to drop i…
In theory, yes. In practice, no. The US had no incentive to drop it, so they wouldn't do it (they could have done it a long time ago if they wanted). Now, they have an incentive to think about it and talk to the EU about a treaty which drops it for both sides.