Agency is such a ridiculous argument that's been used to promote exploitation for ages. Black people just choose to participate in sharecropping, Chinese women just choose to bind their feet, women just choose to be prostitutes who get murdered at 4 times the rate of the next most dangerous jobs. It's only in retrospect that we view these as atrocities
And to pretend that this is some vacuum that athletes are making this decision in is ridiculous. Allowing steroids in competition means that you have to use steroids to compete. Were you capable of making these types of decisions as a child? Do we allow children to harm themselves or do we condemn it? Should we allow adults to do this when there is a very clear external factor that motivates them?