Ooh, big goal post shift. Again.
I've said nothing about the EU response to the pandemic. However, the EU's trading mechanisms helped keep the UK supplied with goods that people wanted. Brexit will put barriers in the way of that and would very likely have quickly made the situation here extremely difficult.
As for the Yanks' working conditions- they're fucking awful. You're outraged at the Leicester clothing factory or the Herefordshire farm? Because of Brexit, we're going to be supplied by the US, whether we like it or not, and their food processing plants are exponentially worse than they are here, both in terms of working conditions and worker exploitation. Yet another Pyrrhic Brexit 'victory'.