I didn't see any of this conspiracy talk before the pandemic that I can recall, but I'm guessing this isn't a whole new mindset they've adopted. They've clearly always been a bit thick.
The twit saying there's no proof the virus exists completely poo pooed every bit of evidence I've offered from scientists, doctors, epidemiologists, first hand accounts from people who've been critically ill.
Everybody is lying, apparently.
If you do manage to convince one of them that at the very least a virus exists, then they'll tell you ok so it exists but it's massively blown out of proportion and the government has done that purposefully to crash the economy because they want to get rid of physical cash and have us all given a basic living allowance regardless of the jobs we have 
At first it was all due to 5G, then a new world order, wanting to get rid of money and have us all on a basic allowance.
I've even had some moron repost something saying that the virus doesn't exist it's a smokescreen to distract from the fact a meteorite is coming and lock down is because Boris wants us all to spend our final moments with our families.
They conveniently ommited to include we were explicitly told not to meet with family members at all if they don't already live in our household.
I think I have to face facts that these people are just nutters. They're individuals I grew up with, who all still reside in our small home town so have no real concept of life outside of that bubble.