Have there been any studies into the long-term effects of removing natural-selection from a gene pool?

It seems to me that as a species; so many people are living and creating lives that would otherwise not have existed in the natural world. People with disabilities, diseases, or even infertility are able to thrive in this world and pro-create.
I know my appendix should have burst after my first kid, but here I am with 2 sons.

Is this unprecedented? Have any long-term studies been conducted on this? If not then there’s a PHD paper for someone lol.