I got dizzy by your own confusion on this subject.
You need encryption for the same reason you need locks. Locks are not the only trick to provide you security but they are pretty much a very necessary tool. Without solid encryption you can't have a lot of the good things on the internet: online banking, online shopping, filling taxes online,...
> it is still pretty easy to create a virus or something that access the data at the moment it is used
It is not so much anymore. Viruses are getting quite harder to make, even for Microsoft Windows. And, even if you were right, you still need encryption for people that are smart enough to avoid viruses.
My point still remains. Even if you have good encryption, pure reliance on that puts you at risk in so many other ways in which information can be accessed. Any time you see information, access your bank accounts, create an email, etc., your information is at risk, and that has nothing to do with the amount of encryption you're using, because encryption will only work during the data transfer/storage stages.
You need encryption for the same reason you need locks. Locks are not the only trick to provide you security but they are pretty much a very necessary tool. Without solid encryption you can't have a lot of the good things on the internet: online banking, online shopping, filling taxes online,...
> it is still pretty easy to create a virus or something that access the data at the moment it is used
It is not so much anymore. Viruses are getting quite harder to make, even for Microsoft Windows. And, even if you were right, you still need encryption for people that are smart enough to avoid viruses.