I would add my voice to cautioning against such sweeping generalisations. Saying "I'm a layman... our understanding of the brain is very basic" doesn't really follow.

The brain is something of a black box, and it is extraordinarily complex. We have a complex understanding of it - which isn't enough to understand it fully, but it's better than 'very basic'. The characterisation of our understanding as being so simple doesn't do either the brain or the researchers any justice at all, and makes us lean towards it 'being okay' to be helpless in the face of its complexity. It is, without a doubt, the most complex field in the human experience by far.

all the treatment often seems to do is to alleviate the most visible of the external symptoms, causing several new problems in the process, or simply making the patient apathetic

Some patients generally do okay with medication, others have transient episodes during which the medication helps throughout. Not every patient is on a rollercoaster to hell. If the argument "well, you can't save everyone, so don't try anything" really had any merit, there wouldn't be any Emergency Departments in hospitals.