Amazon.com’s ability to make next-day deliveries is being hampered in some parts of the U.S. due to a lack of warehouse staff and drivers. “We have unfinished business on the one-day-promise side. We were ramping that up nicely in 2019 and in the first quarter of 2020 before the pandemic,” said Amazon CFO Brian Olsavsky. “We’re still not back to levels that we saw pre-pandemic.”