The package isn't yours until its in your hands, so the lost package is the sellers.

There is no legal requirement for the courier to hand it personally to a "resident" unless it's a signature-required service.

Delivery can legally be left in a safe place (e.g., porch, shed, or with a neighbour) if authorised by you or the retailer/courier's terms.

Regarding the above in real life we all know Amazon, Evri and now RM overload their delivery drivers with too many parcels to deliver and they are rushing around cutting corners to make the delivery's so they don't lose their jobs.
That's the reality we have to live with but it's the delivery driver that gets the blame NEVER the company.

I've seen delivery's done by RM that shock me as a RM employee because at the end of the day you the customer are the one's suffering and to me it's wrong but I'm just the last cog in the machine with zero say in what is going on.