There is a lot of wisdom in this post, but a lot of problems with the "modern masculinity" and contemporary personal development narrative. Get ready to be challenged, for it is in the fire of rational analysis that truth is tested.
"I stopped being a nice guy and started giving fewer fucks. I teased. I said mean things." We have a crisis of civility in the US, where nobody cares about the psychological harms we do to others. These harms are real and have real, lifelong, physiological consequences. Bullying is not OK, and the modern masculinity movement is a rebellion back to regressive forms of the gender. Yes giving too many fucks is not beneficial (I've read Manson) , but doing harm to others is sociopathic. The people you harm become the next mass shooter, wildfire arsonist, or dependent on the social safety net, which YOU have to pay for one way or another, whether it is through taxes, walking through the feces of a homeless encampment, or paying for fire suppression. The effects of your actions come back to you. Karma.
The girls liked you because you hacked their chimpanzee brains- the appeal of the violent alpha. There is no paradox here. This is a truth that we should work to change, to become more than monkeys.
The More You Try to Impress, the Less Impressed Everyone Will Be
That's because a concerted effort to impress is less likely to represent an authentic fitness signal. If you can impress with less effort you are more fit.
What You Hate Someone Else for Is Likely What You Avoid in Yourself
Sometimes but not always. This does happen, but is far from truth. Obviously hating others is never a good response, so deal with your quote “The flaws you see in others are actually a reflection of yourself.” So holding abusers accountable is actually due to ourselves being abusive? HUH? Nonsense. This axiom prevents critical evaluation of the flaws of others and perpetuates entrenched inequality and power structures.
People Who Don’t Trust Can’t Be Trusted
Again, not a rule. Many people don't trust because they've been violated, not because they are liars. The world is full of scammers and cheats, not because I am a scammer, but because exploiting others is a successful way to secure resources. This principle breaks down healthy skepticism that would undermine the simplistic views presented here. Kinda cultish, like much of the hipster "spirituality".
You Succeed Not Despite Your Failures, but Because of Them
Again...sometimes. Many people have career ending failures from which the only lesson to be learned is not to take excessive risk. People can be ruined (Martin Shrekli, Carlos Ghosn, Elizabeth Holmes, etc). Bouncing back is not guaranteed, and the cost of failure can be catastrophic. We don't talk about the unrecoverable failures and so there is a huge visibility bias. The social engineering value of this principle is that individuals are expendable, and society benefits hugely from the innovations of the few whose risk pays off.
What Scares You Most Is Your Biggest Chance for a Better Life
Possibly, but like the last "truth" the risk of catastrophic failure is real, and fear is our brains calculator of that risk. So the question is not to challenge all fear, but to perform risk analysis on our fear. [Some] social fears are valid to challenge, physical and economic ones not necessarily. Ditto the last one for the social engineering outcome.
The More You Can Have It, the Less You’ll Want It
Yep, 100%. Avoid the hedonic treadmill
More Choices Mean Less Satisfaction
Within a range. People whose choice is between abandoning their family and community or go on living next to a chemical plant or in gangland are not more satisfied. This title should be "Too many choices..." not more. Generally well covered though, particularly the quote.
“The Only Constant in Life Is Change”
Yup
Problems Make You Happy
Provided you have the resources to solve them, and that they are tailored to your abilities. Yes, generally true.
If "modern masculinity" simply becomes a repackaging of the toxic old masculinity with some new age verbage and salt lamps, we're in trouble collectively, as that old masculinity has created a lot of very negative externalities.