The problem isn't trucks -- obviously, it's hugely more efficient for a single truck+driver to deliver 100's of packages in a single day than for 100's of individual people to spend an hour each going to/from a store, and even worse for congestion if even more than a few are taking individual vehicles. The problem is parking. And the solution is obvious: multiple truck-length parking spaces along each and every block…
No, there should not be street side parking on most streets as this becomes a huge hazard for cyclists with uni students randomly swerving in and out to deliver a pizza or people carelessly swinging doors open to get out of a taxi without looking. Inside a city, for most kinds of deliveries, it would be more efficient to have people deliver by e-bikes. A bike with a trailer or large bag is an incredibly efficient way…
As for package size ... I’m not sure there’s much of anything delivered to my building on a daily basis that could be transported up hill by bike.