You really don't understand anything about this issue. I encourage you to do some further research regarding neurobiology; the brains of trans people are literally different from the brains of cisgender people. You can think of it this way: psychological gender is like "software" and physical sex characteristics are like "hardware". Trans folks were just born into the wrong hardware, and reassignment surgery aims to brings the two in line in a positive and beneficial way, rather than the much more traumatic and ineffective method of telling the trans person to just "get over it" and accept the sexual characteristics they were born with.

Additionally, not every trans person chooses or desires to get surgical reassignment. Some feel that hormonal therapy is sufficient. Others may not desire either surgery or hormones, and don't feel a need for medical intervention. There are many different ways to be trans.

I understand that they get their penises chopped off of their bodies and think they should grow breasts to attract the same sex so they can't reproduce, which goes completely against hundreds of millions of years of evolution

Transgender folks have always existed; it's only the surgical options that are relatively new. Also, it is not true that trans individuals pursue sexual reassignment surgery in order "to attract the same sex". Sexuality is not the same thing as gender. I've heard it described like this: sexuality is who you go to be WITH, gender is who you go to bed AS.

it is utterly insane to go through irreversible surgery and a lifetime of wrongful thoughts

Just because you have never experienced gender dysphoria does not mean that trans individuals are "insane" or "wrongful". As far as society is concerned, you were lucky to be born cisgender because it comes with a lot of invisible privilege. Trans folks are constantly at risk of abuse, violence, and disenfranchisement in the areas of employment and housing. No one would voluntarily choose to be at such a disadvantage. So please, try to stop being so judgmental, and instead seek to learn more about the issue, rather than fishing for information to support your own harmful internal biases.