Being able to find a delivery point (and potentially avoid being bitten) will doubtlessly be something that drivers will appreciate, but not having to carry a handheld GPS means they will be expected to carry even more packages. Also, Amazon could use the glasses' time-saving abilities as an excuse to increase drivers' stops per hour target – they currently visit more than 100 customers per shift.
The project could be scrapped or delayed indefinitely if the glasses fail to work as intended or they end up costing more than the money they might save.