Different kinds of people sport different chests. Women (that is, people who identify as such) have boobs, men with a little extra weight have man boobs, and female-to-male identified people* have a chest to which they might refer using neutral words, like chest blobs. That´s how I call it, anyway. Chest blobs are different than boobs. Boobs, I think, are usually appreciated.
Appreciated by others and by its owner. Chest blobs on the other hand are mainly obnoxious, and often the person sporting them will want to undergo a surgical procedure to have them changed (though not always). Personally, I´ve never admired chest blobs with the kind of reverence boobs get. Judging by the stories I´ve heard, people who have boobs actually enjoy having them.
This is why I wear a binder. A binder is a tight top that you wear under your other clothes. Contrary to a brassiere, it flattens and evens things out. They don´t hurt (some do, but in my opinion they shouldn´t – if you´re wearing a binder that hurts, I´d advice to get a different one or do some DIY). They can however restrict free breathing a bit depending on the size and in summer they are hot like hell.
They can also create an awkward chest when it meets any pressure. By which I mean biking downhill or biking in strong wind. And while I fixed myself a solution for this (fixing stuff I don´t like is my thing), on hot summer days I don´t want to be wearing tons of restrictive clothing. So I have to resort to another method. Which means I hold my shirt at the bottom to even it out.
The other day (before my re-injury) I was biking to one of my favorite places and this happened. I felt funny though. Would people know what exactly I was doing? ´Cause it looked like I was trying to cover up something else. It looked like I was trying to cover up a stiffy. Which is worse? If it looks like I´m sheltering a tentpole, at least it will match my gender, but… yeah.
I guess the moral of the story is: binders are great for chest blobs the way brassieres are great for boobs, but they definitely have downsides. Personally I would rather have no chest blobs of any kind, so people won´t think I´m raising a drawbridge, and I would really enjoy just going for a swim, but that just isn´t in the picture right now. I´m looking forward to those things.
*Preferring a flat chest isn´t just for transguys though. Nonbinary and genderfluid people, who aren´t on either side of the spectrum, or just not comfortable on the spectrum at all, might also prefer it.