I post a lot to Europe for work and its a bit of a gamble when it goes wrong. RM are totally useless overseas – declining responsibility etc.
However – I honestly think very little actually goes missing – but sellers overseas are almost never asked for a sign for a RM “signed for” item – so they have a world of options for messing about.
I believe a lot of it is down to the customer – what are they like, history etc etc.
And sadly some countries are way worse than others. Way way worse. IME – France, Germany, Holland, all nordic countries dont have common issues. I know thats a generalisation. Everywhere else from me is DHL or similar (parcel2go is good usually).