Why are disposable vapes allowed but you are no longer allowed to remove the cap from plastic bottles?

Because lobbying works unfortunately.

Rather not, because an EU-wide ban on disposable equipment is already in work. Only until a regulation with the EU is passed through all instances and is subsequently adopted into national law of the Member States, it takes quite a long time. Especially if the EU does not see an acute need for action…. (There are other decisions that are far more important, which appear to us as meaningless.)
Member States are, of course, able to adopt appropriate laws in their own field. Some are already doing this. A corresponding draft law has already been introduced in the Bundestag at the beginning of last year – only one wanted to wait there for the results of the EU in order not to have to change a law that has just been adopted directly. (Maybe this is only a delay tactic on the part of our policy. Finally, the one-way things wash tobacco taxes into the empty cash registers.)