Why expose ourselves to the virus?

Why expose ourselves to the virus?
The situation in singapore has become more and more worrisome. Why have some classes at home and some in school? This petition is to voice out our concerns of our safety and health during these trying times.
Hypothetically, we are more likely to contract the virus on our commute to and from school. This will cause a big cluster and have a greater effect on us mentally. Do we really know what we are coming in contact with when we are out of the house? Are we really as safe as everyone says we are?
Evidently, classes conducted at home can be just as beneficial as the ones conducted in school. With less time spent outdoors, we are less likely to be in danger or spread the virus. We would also have more time to ourselves to do our work, focus on our mental health or any other priorities we have.