Oh there are reasons for it but they're not for this forum. I have two orders coming from Pedal PCB, the first posted 15th of October. I still haven't seen either but I know it's not Mr PCB's fault.
One reason I will mention is that airmail doesn't always go onto dedicated mail flights. A lot goes as freight on regular flights, and because of Covid there aren't the same volume of flights at the moment, so there are fewer opportunities for our parcels to hitch a ride. But that's only one excuse. Everything else makes no sense at all!