I was happy with the EEC which was what the country actually voted for in the first place, i.e. benefits of easier trade etc.
Over the following decades, I have become increasingly unhappy about all the "scope creep" that have been enforced on us without public consultation, such as freedom of movement of people, the ECJ, EU tax interference, suggestions of an EU army, basically, the creeping of the EU superstate.
Yes, I fully appreciate that some of these issues were worsened by our own government blindly accepting things we had the power to veto, such as free movement of people from the countries more recently admitted into the EU.
But, for me, it's just gone too far towards the European superstate and I want that rolled back towards what we originally voted for, i.e. the EEC trading area.
As for the "benefits" of the EU, i.e. human rights, safer consumer goods, cross-border co-operation, etc., we could have done all that without being part of the EU superstate. Nothing to have stopped us adopted the similar rules as the EU when it comes to human rights or electrical safety, but we'd have been in control! As for cross border co-operation, just look at Concorde - a joint venture between the UK and France before the EU superstate existed. As for security, we have reciprocal agreements with security services in countries outside the EU so why can't we have the same with EU countries without being in the EU? Re worker shortages, we already "import" workers from non EU countries, so why can't we make our own rules to "import" EU workers where needed - i.e. have a work visa system for jobs where there are shortages.
Nothing has convinced me that the scope creep towards the EU superstate is beneficial - nothing has convinced me that we can't collaborate with neighbouring countries without being in the EU - nothing has convinced me that we can't still attract immigrants for areas with skills shortages. If we are in control of our own laws, we can decide whatever we need to do to import goods, set our own VAT rates, set our own immigration rules, etc.
The only problem is that we need politicians and civil servants able and willing to actually put the work in, rather than lazily copying and pasting the EU legislation we blindly follow at the moment.