A common female contraception is the pill, something that is made from estrogen and progestin. This is 91% effective over the course of a year with typical use, 99% effective with perfect use.

Condoms can be cumbersome, vasectomies require more surgery to reverse, and pulling out is, well, not exactly a reliable form of birth control. That may be why a majority of men in surveys have said they’d welcome a hormonal birth control pill, and also why most leave birth control to their female partners. - Vox

Male hormone specifically is schedule 3 while female hormone is excluded. "anabolic steroids, testosterone" are considered part of schedule III

For certain people, despite difficulty and limited testing done due to barriers created by scheduling of the drug, we could have a 90-100% effective contraceptive. "study volunteers in Asia exhibit rates of azoospermia in the 90–100% range on testosterone-alone regimens"

in Chinese men. No pregnancies were recorded among men who were azoospermic or severely oligozoospermic (<3 million sperm per milliliter), providing a 95% upper confidence limit of pregnancy (contraceptive failure) rate of 2.5% per year.

JCEM. That means it is 97.5% effective, similar to that of the pill. Despite that, there is no male contraceptive available.

In European people, it had lower rates of 60-70% effective. This is already helpful on it's own and can limit pregnancies especially when coupled with other contraceptives.

As a thought experiment, consider a child free couple just using the pill. Over 15 years of being together (say ages 22-36), with the pill being 91% effective each year you would expect 0.09 pregnancies a year, or 1.35 from ages 22-36. If this could be cut into a third by an additional contraceptive, that would lower the 1.35 unwanted pregnancies to 0.45. (Note due to potential statistical dependence results may differ, but you would still see reductions.)

More studying needs to be done and can create potentially more groups of people with high (>90%) effective rates. For example, similar to plan B not working on women at 165 lbs, there may be a weight component to efficacy at play here that I haven't seen studied anywhere.

It is hard to say how much drug scheduling has an effect on having an available male contraceptive versus other factors such as perceived financial gain from pharma. Also, for the life of me I have spent over an hour trying to find out what the difference between the different schedules are for how you can get studies approved or get medication approved, but have had zero success outside of tiny tidbits for schedule 1 and 2 drugs. (Schedule one can not have medication, schedule 2 has to have dea approval and is not common, for both there are very few places it is federally allowed to be produced.)