It's a bit disingenuous to say that not being part of the EU has had no effect on the UK's vaccine programme.
There was a scandal with France slowing down purchasing of more vaccines because they wanted more Sanofi vaccines (French) to be bought instead of more Pfizer (German). Germany conceded (whilst also buying more vaccines on their own in a side deal), and this is one of the reasons why there will be a delay here where I am (France). I will be getting the vaccine much later than my friends in the UK are estimated to get it.
Personally I voted Remain and then left once the results of the referendum came through. Now five years on though, my views have softened, possibly as a result of being in a region of the country that votes Front National - my in laws for example would all vote for a Frexit if that were an option.
On balance I would still vote Remain and I'm pissed off that Brexit has fucked up my own red tape and situation. Ultimately though as someone who has worked in many countries outside the EU, and having checked what I would need to do if I wanted to go to another EU country outside France, the hoops arent that difficult to jump through - I know its unpopular and goes against the "they've banned us from ever exploring the world" narrative, but it's true.
In France for example, there were a lot of things already in place pre Brexit that make it pretty difficult to get work without being French, unless you are highly specialised or work for a multinational (in which case you wont have problems post Brexit) or go into English teaching. In fact with the latter, you cant even rock up and teach in state schools the way you can in the UK - you have to sit the "concours", a series of very competitive and academic written exams, which effectively bars many non French applicants from entry as they are heavily geared towards the academic logic and mindset that French people start developing in primary school. That's why many native English speakers end up working for private schools, or on short term year by year contracts, unless they are very motivated and throw themselves into studying for the concours.
Anyway I'm digressing but the point is I dot think FoM is too much of a disaster, especially since I think we will have another two years of posturing before the UK is quietly assimilated under the same rules as Norwegian and Swiss citizens seeking to move around
The UK has a huge number of faults, like all countries, and can be a harsh place to live - I'm thinking particularly of disgustingly low protection for tenants and low wage workers. However the UK had always been a business minded country and one with a flexible and supple bureaucracy, plus a forward thinking outlook in terms of business affairs. With that in mind, I think they will make Brexit work. It's just obvious to me that as with any major change, you wont see those benefits immediately.