These disasters themselves do not help the people who live in these regions. However, volcanic ash, in non-devastating quantities, is full of minerals, which enrich the soil. Many people risk living on or near volcanoes because the soil is good for farming. Volcanoes are also popular tourist attractions, which can help build up the local economy.
Earthquakes can cause serious structural damage to buildings and can be deadly to citizens, especially during the aftershocks. Volcanic eruptions can mean people need to be evacuated quickly, leaving their homes and possessions behind possibly to be destroyed. Both of these types of natural disasters occur unexpectedly, meaning there is often little warning or time to get somewhere safe.
In terms of buildings, architects in the Philippines design these in such a way that the buildings can move and sway without collapsing, something that is essential when an earthquake hits. There are multiple ways to build large structures so they are more "earthquake-proof." One way is to use tuned mass dampers, (sometimes called seismic dampers). These devices can absorb some of the energy of the earthquake and keep the building from moving as much.
For the volcanic ash mudslides like lahar that can occur after an eruption, causeways have been built to direct the flow away from houses and civilization. Additionally, it is common for towns and cities near volcanoes to have planned evacuation procedures in case of major eruptions.
