No-one understands macroeconomics well enough to know. They all feign certainty based on their general worldviews.
Go back and watch various economists debating issues in the past, in cases where we retrospectively know what the outcome ended up being.
I remember seeing a few Nobel Prize winners debating something like government spending after the recession. The US didn't really cut government at all. Whereas the UK did quite a lot. Half of these economists supported 1 policy, the other half supported the other. Now fast forward 5 years and see what happened. UK and US growth are almost identical! It made absolutely no difference what they did.
I don't understand the democracy argument when our own system is no better. The House of Lords is filled with hundreds of unelected people that can dump any legislation they don't like. And it's not like we get to vote for which politicians end up in the most influential cabinet positions (I sure as hell wouldn't vote for Hunt or Gove to run anything).
With the EU we vote for our MEPs who represent about 10% of MEPs so we have good overall representation. The EU commission that propose laws are made up of 28 representatives and each one is determined by the leader of each country. It's not different to any other civil servant. They can't actually pass any laws without the agreement of the MEPs (who, as I said, we vote for).