FSD is hard, yet drones want to do FSD in 3D. They will constantly run into trees, power lines, etc. Also, they will always be targets for kids or people believing they are spying on them. Finally, there is a REAL issue with porch pirates and drones can't usually get anywhere near a porch. Who wants their stuff placed in the middle of their yard? Also, this can never work with people who live densely like apartments.
The real drone delivery solution will be vans who text you that they are coming. Once you confirm they roll up to your home and let you know they are there. They send you a code. You go to the van and type in the code and a door opens revealing your item while taking a pic to validate the recipient. In the meantime its already texting the next couple deliveries ahead. If you aren't home you can tell it you'd prefer delivery at 2AM or whenever is convenient. That's noted and it will return then. This method eliminates most failed deliveries and theft due to unattended packages or lying customers who state they never received the package.