>>11346637We have mapped the majority of stuff but it has taken a lot of time and effort to get to this point. But it is not that different to understanding binary from a computer. Google Single Nucleotide Polymorphisms to learn how we came to most of our genetic knowledge.
We can and have used genetic knowledge to our advantage for decades. What stops us is a combination of ethical concerns, like is it OK to experiment on living people, is it ethical to make permanent changes to the human genome, etc. There are very few situations where we can say with absolute certainty to that it is OK to permanently remove a conditon from the genome and even less of an ability to predict what impact those changes would have long term.
Technology-wise, we have been able to do designer babies for decades.