Here in New Zealand where very few people died of COVID, overall mortality dropped significantly during lockdown. This seems to have mostly been due to a lack of traffic deaths, air pollution improvements, as well as a massive reduction in non-COVID respiratory illnesses. This article actually posits a reduced number of complications from elective surgeries as a factor in the reduced death rate: https://blogs.otago.ac.nz/pubhealthexpert/2020/07/10/weekly-...:

For example, around 40% of Wellington ICU patients are typically from elective procedures and around 10% of all Wellington ICU patients die.