Are we ruining our genes /sci/?

I mean natural selection doesn't really apply to humans anymore.
Disabled people, people with gen defects, people with poor physical or mental health, they all can get treatments and have a somewhat normal life and procreate.
I don't want to sound like a polnazi but as you can see the "weak" aren't dying anymore and their bad or defect genes mix with other humans, doesn't that cause humanity as a whole problems in the future?

Another thing to consider is that educated people usually have less kids than uneducated people.
Not sure if that is a problem, but I personally get the feeling the average joe is getting dumber and dumber.