I should start by saying I have 2 very young kids and barely leave the house, so I've taken to buying almost everything online, and mostly ebay to be honest.
I'm all good with secondhand, for budget reasons more than anything else but I also buy new off there as it's cheaper than other shops.
This month alone I've had a tin of paint posted in just a black bin liner, leaking when it arrived, kids tee shirts with felt tip stains, new shoes from a business seller 5 sizes too small, a leapfrog junior where the leaking battery acid means it won't turn on, charged double postage costs for clearly recycled packaging (in general doesn't bother me, but doesn't seem worth £4!) and several things just not turn up at all 😩
Obviously the more you buy the more issues you will have, but bloody hell, it seems some people will just sell any old tat, and others just have no clue what they're doing.
I get as a seller there's a lot of shit buyers, but as a buyer there's a lot of shit sellers.