Idea: Position a fleet of blimps (which are capable of up to 200 km/h) in such a way around the world that every major inhabited place can be reached in 5h. I think you need something like 20 or such bases.
Also, these bases have cargo containers that can be strapped to the blimps. A container with an emergency operating room (including doctors), with fire fighting equipment, with water purifiers, telecommunication hubs (starlink and such).
Scenario: an earthquake of 6.8 magnitude, e.g. in china (as just happened on 5.9.2022).
The blimp starts flying to the affected area. At the same time trucks/trains/ships carry the proper containers alongside, but much slower.
The blimp drops of the container, flies to the trucks/trains/ships en route, picks up another container and brings that to the affected area.
If the disaster is big maybe a second blimp, from farther away, also starts but takes longer because further away. Can also ferry containers to the affected area.
Costs in total: very rough estimate ~ 200-500 Mio. $.