Citizens of the UK elect members of the UK Parliament. Candidates and political parties put forward manifestos of the policies that they intend to enact if elected. MPs can vote for or against Bills and propose amendments. Individual MPs can also propose laws (such as the current assisted suicide scheme).
MEPs and their parties stand for election with no specific manifesto policies as they have no power or means of proposing laws in the EU. All they can do is put forward to the electorate their general outlook, for example UKIP stating that their aim was to remove the UK from the grip of the EU. They can vote against laws presented to them by the unelected EU Commissioners, but in the case of budgetary and foreign policy matters they can’t even do that.
EU law overrides national law. That meant that the UK (along with other member states) could not pass national laws that contradicted EU laws. It also meant that an EU law could over-rule a UK law, even if that UK law was enacted before the EU law came into effect.
If you can’t directly elect the people that propose and enact the laws that govern you, then you don’t live in a democracy. Certainly, the EU parliament is a puppet parliament. The British electorate recognised this and wisely voted to leave the EU.