Max payload is only 31lbs unfortunately
https://www.nga.gov/collection/art-object-page.220510.html
https://www.mentalfloss.com/article/20908/why-are-st-bernard...
the helicopters are necessary because they need to carry large loads that can't be divided up, which a robot with a 30lb capacity can't help with.
With improvements in programming, that's not necessarily true considering they have four legs.
> people can also operate for longer than 90 minutes.
Note that the 90 minutes is without payload. With payload it's likely much shorter.