Why have the adverts for buying gold increased since brexit ?

When economies are in trouble, which they are across the world at the moment, whether due to leaving the EU, or because the virus (which you can't ignore) has shut down pretty much everything, buying gold is security.   Has ever been the case.   The Germans under Hitler, had massive reserves of gold.

They're making money hand over fist from the public, buying their grandma's locket handed down for generations, only to be melted down in to ingots and sold to the wealthy who can stock pile it in a banks vaults as insurance in case/when civilisation collapses. Come the good times again, they'll sell it back at vast profits as a limited edition commemorative coin celebrating the war you won. I understand a lot of gold in circulation goes back to ancient times, where it was looted and melted down from what would now be considered priceless artifacts. Obviously it doesn't disappear, just gets recycled.

They haven't and you are a liar.

It's something that has value anywhere in the world. No use in buying shares in British companies that have had half of their trade cut off.

You don't think it might be something to do with a global pandemic, do you?