A well-run regular all-hands (every week or 2) can have a profound impact on a company. It can...
Set a cadence for the whole company
Hold departments accountable for delivering big wins on a regular basis
Force the leadership team to capture and summarize their thinking to the rest of the business on a regular basis
Build trust between all stakeholders
Help stakeholders across the company become aware of new developments and encourage people to jump in and help/align
And so much more!