This article goes into detail for those interested and recalling the reports that “ventilators make COVID worse!!!?;!!?” spread by dipshits that then deny COVID was a problem at all.
TL;DR patients who were put on a ventilator for pneumonia frequently show improvement. Because ventilators do indeed work as a last ditch treatment.
The problem is that if they develop a secondary infection, an inherent risk of the procedure and one of the reasons why it is a last resort, the person who was going to die without it probably won’t respond to further treatment.