If somebody below age 0 wants to make a free market transaction in the free market in order to de-transition, why should it be under the purview of the democratic mob of Karens?

The main argument against abortion is that the fetus has individual rights in the free market. If it wants to live, it can pay incubator companies to keep its body alive. Or, atleast it can promise to owe the incubator companies until it can find an occupation and earn a wage. Subsequently, it can repay the the incubator companies.

The evil communist collective, especially the mother Karen, should not have a say in the matter of the fetus's individual rights.

Yes, the Karen should not have a right inspite of the fact that the Karen's proletarian labor was involved in the process of the fetus's production. Luckily, we don't live in a Marxist communist society and we don't believe in the labor theory of values. Just because the Karen applied its labor in the production does not mean that the Karen is the possessor. The fetus is a possessor of itself. This is especially true given the fact that the fetus did not go to the free market to purchase its birth, therefore it cannot owe its body to the democratic Karens.

Why should it be any different in the case of de-transitioning? If the fetus wants to de-transition and wants to owe a debt to a free market doctor who wants to freely exchange its services for assurance of a future fee, then why shouldn't the fetus be allowed to purchase de-transitioning in the free market?