I was adopted when I was about 3 months old. I have no recollection of my birth parents and despite my adoptive parents giving me the requisite information in a sealed envelope on my 18th birthday almost 30 years ago, I have never wanted to seek out my birth parents. I have never felt any of the sense of loss or not belonging that some adoptees express (and as often portrayed in film and TV). Whether this is just part of the way I'm wired, the relationship I have had with my (adoptive) parents or because I'm an only child so had no-one else to feel different from, something else or some combination of factors - I don't know.
IMO describing adoption as slavery indicates that the writer either doesn't understand adoption or has had a horrible experience of it. It's not something I recognise.
QFT. I was adopted 10 days after birth through an unregulated Catholic agency (which was the norm at the time). Apparently my biological parents were students at the University of Washington at the time, and abortion wasn't legal. Had it been, or with fairly easy and safe underground access to it, I wouldn't be typing this right now. Nor would I know it; needless to say I'm ardently pro-choice.
Blood lineage is fine, but so is non blood-lineage. There's too much emphasis on genetic background. The only time it really comes up now is when my doctor, always forgetting about the last conversation, asks if there's any history of X disease in my family.
Like you, I never felt strongly about finding out who my biological parents were. I was lucky enough to grow up in a stable, loving family relationship, and that's really all one could ask for.
My sister, however, who was also adopted (unrelated to me), did meet her biological mother in early adulthood and it was a disaster...substance abuse, domestic abuse and everything you would not want to hear about your DNA.
It's a crappy right-wing article with little to back up their facts, more clickbait than anything else.