At least in most Western countries, we have explicitly outlawed the same medicines (Anabolic/Androgenic Steroids) for non-trans people without a physical medical need. In other words, a man who feels dysphoric about his body not being masculine enough cannot access the same drugs that a (biological) woman who feels dysphoric about her body not being masculine enough can.
I'd guess there are biological females who genuinely benefit from transitioning with testosterone, much like how there are many males who benefit from it due to hypogonadism/similar issues. I would have a serious problem if people started pushing testosterone on vulnerable young boys and telling them it would fix their problems, while vehemently attacking anyone who remotely questions those claims. How you think that's acceptable in girls, and compare it to informed adults getting botox for wrinkles or rogaine for hair loss is astounding.
None of the drugs you listed have significant effects lasting longer than a few months after their usage is stopped. With regard to plastic surgery, I'm not aware of any widely practiced cosmetic surgery that permanently and drastically changes one's entire endocrine system. If you're talking about cosmetic surgeries like breast implants, I don't think anyone has a problem with either trans or non-trans adults spending their money to look the way they want to. There is certainly no law to prevent it.
A man with low testosterone can’t get it because it’s “cosmetic” but the state will pay £100k for a child to have their penis removed for cosmetic reasons. And a lifetime script for the same hormones that people with medical needs aren’t allowed.
The medications and treatments often prescribed for trans people typically have other uses, so unfortunately for those who want to ban trans care, it's not possible to ban the treatments entirely, just come up with policies for being really selective about it. Those policies will not be terribly fair or effective.
Otherwise you're denying other people access to the same care even though you might believe they need it - reconstructive plastic surgery for cancer survivors, androgen or estrogen suppressors for people with various hormone regulation problems, hormone replacement for post-menopausal women or men who no longer have functioning gonads, etc.
Incidentally the latter is why Californian insurance typically covers surgeries for trans people: They already cover the same surgeries for other cases.
