Transhumanism is unethical and should not be something brought into everyday life because it may give unfair advantages to humans and cause competition within society. Per the Wikipedia article, transhumanism is a movement that supports advantages to human condition, physically or mentally. These advantages can stop disabilities, promote immortality, and many other things. I am focused mainly on the physical advantages of transhumanism, because I have grown up as an active and athletic person, and just the word “physical advantages” makes me cringe. I will explain this through example that may make you look at the way your neighbors do things.
For example, if you receive a procedure to your body that increases the speed at which you can physically mow your lawn, your neighbor may observe that also try to find new ways to mow their lawn faster. If people are advancing the way they do normal things every single day, it is going to create a competition amongst people in society who want to keep doing things better and better. Your neighbor will keep trying to top you, and you will keep trying to top them, and mowing lawns that often is simply not good for your grass.
For another example, if I am working hard every day outside playing basketball, and I see my younger neighbor receiving transhumanistic advantages to make them make a basket every single time they shoot, that would feel unfair. They did not have to go through all of the actual hard work to get to where I am, and yet they have a higher skill set than me. They did not have to experience hardships to get to that point. Because of this physical advantage the transhumanist movement has caused, I will now experience hatred for my annoying neighbor.
Tension between neighbors would just be the start if transhumanism became prevalent. It would branch later into greater communities, sports/athletics, politics, and even global problems, and everyone would simply make a competition out of everything.