Augmentation through changes in the genotype is fraught with ethical issues both rooted in the lack of knowledge on the consequences and on general considerations, including the unfair advantage that may be gained by a restricted few (among these extremes there are plenty more!).
In the coming decade(s) we can expect our knowledge to grow significantly but it will take quite some times before we can be sure of understanding all phenotypes implication deriving from genome modification (notice that because of potential cross species effect due to virus infection resulting in gene editing in different species the understanding of the whole landscape is extremely complex).
A more conservative modification would be the one affecting the RNA, instead of the DNA, since this will not affect the offsprings, ie the future generations. This is now becoming within reach (at the moment is still in the research labs) using CRISPR/Cas13d, a variation of the technology of DNA editing.
Our phenotype changes continually through our life (e.g. we get older!) and scientists have understood that in part this depend on the activation of specific genes. By controlling this activation it would be possible to change our genotype. Our genome consists of many “programs”, several of them lay dormant, and some may even stay that way throughout our life. By understanding what is the outcome of their activation on our phenotype it would be possible to activate them (or keep them dormant stopping their natural activation) to shift the phenotype in a certain direction.
We are getting closer to this from a technology point of view but we still do not understand fully the implications and it might be quite some time before we do.
It is clear, however, that there is a huge potential in changing the phenotype by mastering this approach. An obvious application is in the area of extending our life span (and youth!) and there are a number of companies like Calico, doing research in this area. The Fountain of Youth, a myth originating as far back as in Herodotus accounts, is becoming an active, scientific, research area.
Notice that if and when (unlimited) life extension will become possible huge ethical and societal issues will have to be faced.
I have little doubt that epigenetics within this century will provide the tools to influence the phenotype leading on the one hand to defeating several diseases that are afflicting humanity and on the other hand to augment us in both physical and cognitive capabilities.