Looks like you just have not deal with bad traders on platforms. I once found on local aggregator product too cheap to be good (unfortunately at that moment only two stores sell these product).

I stored their number in my notebook and going to my shopping, calling them from bus stop, and they answered me some nonsense.

I made my shopping, and some walk, then opened platform and these shops already disappear. Less than hour.

In other case I managed to make order and paid from card, and also shop disappeared. - In a week I received SMS from bank "your payment returned to your account".