I don't think you can blame eBay as such. There's lots of delays in the process at the moment. I order a fair bit of car and bike parts.
In the last few weeks I've had stuff arrive in 24hrs, and some stuff take two weeks regardless of method. I ordered something two weeks ago - it was sent by Hermes, and seemed to have got stuck in the system (didn't move from the depot for 7 days). Customer resent by Royal Mail, parcel arrived this morning, and an hour later the original arrived via Hermes.
In the same Royal Mail delivery, I also got an empty padded envelope in a plastic bag with 'Sorry' on it!
I imagine normal service will resume once all the Covid stuff has died down, and everyone is back at work properly. Just need a bit of patience and lower our delviery expectations.