There is no difference between these and higher satellites. It still super expensive to get them down because have to stop orbital speed. If anything, VLEO is worse cause they are going faster. Not to mention the cost of getting into space in first place. Plus, need lots of satellites to support dropping things anywhere on world.
Also, it is rare to have anything that needs 30 min response time. Most things can be handled by local resources or wait for an airplane. Good example is that the US is working on hypersonic missiles and deploying them around the world.
Connection, remote sensing, and mesh networking are useful.