See this is the thing regarding all things Brexit there are NO experts because this has never happened before, ergo anyones views be it an expert in a particular field or the common man, (woman, non-gender) are simply that a view, a personal prediction. Just like the predictions to what might have happened to planes and all other electrical devices that relied on a sync clock on the stroke of midnight 1999/2000 or just like a chemical expert wouldn't have known that adding water to molten aluminium would cause an explosion until it happened by accident, which is a fairly recent find given how long water & aluminium have been around.
This is not to say we ignore all views but strike a balance somewhere between those predicting an Apocalyptic state verses a Utopian one akin to hope for the best prepare for the worst because neither side truely know what will really happen.
All bad news comes as a shock & and hearing the words like having to "stockpile" due to Brexit magnifies that shock 100 fold yet in reality "stockpiling" is an everyday occurance by goverments, industries & every household up & down the land i'd imagine, for example the 3 medical suppliers i mentioned earlier "stockpile" their 'meds' here in the UK already with supplies to last up to 10weeks all they are doing for Brexit is adding a further 4-6weeks of stock, it will be the same for energy suppliers such as Shell with petrol/diesel etc even i have stockpiled my Pick Up bars (other chocolate biscuits are available) just in case there's a delay in shipping over from the hannover factory.
The stock market the most volatile market in the world takes its lead & reacts to the daily ups & downs of Brexit reports with 1 day millions being wiped out due to negative press & recover after a few days & vice versa its a knee jerk reaction to a perception & not a direct result of Brexit because Brexit hasn't happened yet.
The only true fact in a no deal scenario is we go into WTO rules which allows us to still buy products, materials etc just as before & just as pre-November 1993 trucks, planes & ships will still roll into the UK we don't implode or get removed from the globe or turn into North Korea we are allowed to deal with any of the 164 member states all be it at different rates until new bilateral agreements are made & for those replying but these could take years please re-read the 1st part of this comment as 'could' is a verb used to indicate a possibility & therefore 'could' take years or 'could' take days no one knowns until negociations start but it won't be 1 way i'm sure countries won't price us out as France will still want us to buy its wine & Spain will want us to buy its apples etc & finally regarding tourism the UK is known as 'Money Island' when it comes to holidays abroad so again i can't see the EU members cutting its nose off to spite its face by playing silly beggers.