I voted Leave for many reasons that have been highlighted, and will continue to be highlighted, by this sad and sorry episode.
The EU is a huge, inefficient, slow-moving bureaucracy staffed by well-paid, unelected eurocrats with the best public sector pensions in Europe. It is good at applying red tape, but little else. It is far too big and too remote to govern individual and diverse countries but it is determinedly set on 'ever closer union'. It refuses to, and perhaps cannot, reform (remembering that embarrassing scene when David Cameron came back from Brussels having been clearly told where to go by Merkel when he asked for reform).
It is dominated by Germany and France. That was always obvious, but no one ever liked to say so. It's now been shown loud and clear. Britain was wanted for its money, but not as an equal political partner.
The EU parliament is a rubber-stamping body with no real powers, full of MEPs enjoying the gravy train but with no real voice or representative role. It's the EU commission that makes the real decisions (such as unilaterally invoking Article 16!!) and the commission is unelected and unaccountable.
Don't even get me started on the court which travels between Brussels and Strasbourg, costing millions in taxpayers' money just to keep the French happy.
The EU is fundamentally undemocratic.
How will the disgruntled citizens hold the EU to account for botching up its vaccine process? They can't. This gets to the heart of the fundamental problem of the EU.
Plus, it's a bully (ask Greece and now the UK), and it's a hypocrite. Despite pontificating for 5 years about how there could never, under any circumstances, be a hard border in Ireland (in order to thwart Brexit and try to maintain the single market), it recklessly decides to create one weeks into Brexit. The EU never cared about peace in NI and couldn't give a fig about the peace process, and they have now clearly shown.