With all of these, at least one party must have access to the internet.
Physical cash on the other hand works while both sender and receiver are 100% offline.
Discussion
That’s not correct. The Bitcoin network itself eventually needs internet to confirm a transaction, but neither sender nor receiver needs direct internet access. A signed transaction can be broadcast by any third party (e.g. via radio, SMS relay, or satellite uplink), similar to how a cash payment can later be deposited at a bank.