All that would do is increase handling effort and make shipping more expensive, with no benefit for companies except maybe greenwashing PR.
Let’s try a real world example. From the outskirts of the city where the already mainline railway connected tram shed would be, into the city center. It’s about a 45 minute tram trip, for which you’d have to load and unload the cargo on each end.
So, you unload the cargo from the train which takes time, store it in a warehouse. Later load it into the tram, should take about the same time as loading a truck. So far, so good.
But instead of just delivering the cargo to your customer directly, you drive it to another more central warehouse using the tram.
You unload the cargo again, and once again have to store it in a very expensive warehouse in the city center., until you can distribute it to cargo bikes. Which once again means handling the cargo.
Only then can you deliver your goods at the customer.
So instead of unloading / storing / loading / delivering at the customer, you’ve added another loading/unloading step, and another warehouse to rent in a more expensive area. Loading and unloading and warehouses are already is essentially the most expensive part of shipping anything - the transport on a train or truck itself is not that expensive.
There are specialized cases where cargo trams can work, but they are rare, and they do not involve delivering goods directly to stores, and do not involve expensive facilities in city centers.
In Dresden for example, VW used cargo trams the same way they would use mainline cargo trains - transporting car parts from one factory to another. That made sense, because both ends of the line already had cargo handling and warehouse facilities in inexpensive parts of the town, and only one loading/unloading cycle was needed. They needed no expensive inner city facilities and no further distribution.
But at that point, it doesn’t really replace trucks, it just removes the need to connect your factory to the mainline rail network.