Keep in mind I was a Remain campaigner - you can find the submissions to HN back in 2016 if you check my post history.
Not to mention that still today a key narrative of EU membership is the EU as a peace project. After 2000+ years of unending war western Europe has not had a single border conflict since WW2. That's in large part due to the EU and it's predecessors.
I would agree with the standards body part. Although I would question why you need a parliament, senate, executive, judiciary, foreign policy etc to act as a standards body and to implement a free trade area and free movement area.
Only 1000km westwards.
The Dutch did give GCHQ strong hints about how to break Argentine encryption though [1].
The EU did nothing during the war in Yugoslavia, and nothing when Russia annexed Crimea.
[0] https://www.bbc.co.uk/news/magazine-17256975
[1] https://www.theregister.com/2020/05/18/maximator_euro_spy_al...
Similar considerations apply for the Balkan wars, that started before the EU existed.
On Ukraine: it's not like the US did anything either. Ukraine is not an EU member. The responsibility for guaranteeing Crimea's security, under the Budapest memorandum, sat squarely with the US and... the UK.
In comparison to remaining, the overall decision to leave whilst putting the deal in place ensure that UK [i] decoupled from a political project it had already negotiated an arms-length relationship with [ii] satisfied the sort of person enraged by seeing Polish shops that we could start denying Polish people visas should we wish to do so, whilst net migration is actually expected to continue at similar levels to before and we now face similar mostly theoretical restrictions on our own ability to live in EU countries and [iii] negotiated a slightly larger share of a fish quota, a political priority which has seen significantly more lucrative industries take the hit instead.
We also have more ability to not follow EU law or product/service guidelines, but whether that's a benefit or not depends on which person you ask who's affected by which regulation
I think much of the EU laws were breakable / bendable / vetoable especially as one of the large members, so I don't think that was really a concern.
The issue was that the EU was held up as an example onto which to project (in the case of the UK at least) some rather right wing economics. The primacy of markets, the need for competition, the unease of public or cooperative ownership, the importance of trade no matter what was being traded, fiscal responsibility i.e. 'balancing the books' which was the theoretical underpinning for austerity.
It will still function in this role, but maybe with less of a role.
In addition . The Common Agricultural Policy. This is a horrific way of subsidising some environmental destructive practices, and in the case of the UK at least a way of reinforcing regressive historical land ownership and inequality issues. This now ends in the UK.
The main thing I see though is that it will force UK to focus on structural issues in their economy and society and environment that were previously at best just ignored (and contributed themselves to the result of the Brexit vote), at worst assumed that they were being handled by an assumed enlightened and benevolent superstrate. When all that existed was just another artificial power structure that was subject to just the same issues of all power structures; politics, vested interests, lobbying, control by capital, corruption. Only it was of a distance from everyday life and normal political scrutiny and engagement that people could just outsource some idealised values onto it and ignore it or at least offer it none of the scepticism and scrutiny that structures closer to them were subjected to.
(Unless you are very well connected evil billionaire, these reasons probably do not align with those of you or your family)