I don't think there's any doubt that the virus can travel more than 2m in air, although 2m is presumably considered about the right distance to minimise exposure risk. Short of someone deliberately coughing in your direction, at least.
Also, whilst I agree that the risk of transmission via packages, etc, isn't known and could be higher, it should probably be sufficient to wash your hands thoroughly immediately on or after handling said package.
The main source of continued transmission is probably because the lockdown isn't being enforced and isn't total. The Government anticipated that compliance wouldn't be 100%, and as long as it's not then there are bound to be still some transmission routes. Compare with Wuhan. Although I don't mean to take the Chinese figures too literally, what is certainly true is that there the lockdown was near-total. No public transport was available, nobody could leave the city, nobody could leave their homes, shopping was delivery only, and so on.
As long as people are expected to adhere to the measures themselves then there remains a risk of transmission, albeit a severely reduced risk. We have, at least, managed to exit the exponential growth region.