Hi. Actually many people change the headjoint, although there are lots of people who are very happy with the original one. Anyway, that is why there exist manufacturers which produce only headjoints, e.g., Ian McLauchlan, J. R. Lafin, Drelinger, Tomasi, and Faulisi. And many flute makers sell headjoints separately, and separate headjoints (both new and second-hand) are being sold at flute shops. As for me, I have two c-flutes: I am using the one (made in early 1980s) with the original headjoint, but I have changed the headjoint of the other (made in the US) to Pearl PHN-3, which is not well-known but a very nice one.
Good luck with your flute.

I have tried swapping mine any my sisters flute head joins to try it but i didn't like it because it is a differant cut, i also tried her foot joint but it felt diffent because the cork wedge thing underneath the d sharp if different we also tried my head joint one her body but i don't like the closed holes on her keys so we have just kept our flutes as they came, but i'd imagine if you had nice flutes you liked all the parts on it the tenons were the same size it would be fine and you could mix and match.

Basically this is like a suit. Off-the-rack stuff works pretty well, but almost anyone who cares (or in this case, is a good enough player) tosses the stock headjoint and gets one that is custom made to their needs.

Most professional players have several and use them for different types of music.

I always change my head joints! It gives such a change in sound, it's great to have that option, especially if you are going for a different sound or want practice changing or improving your embouchure a little. Each of my head joints are different cuts and this also helps with having to change to piccolo in the middle of pieces.

A different headjoint can make a huge difference. You might love or hate the same flute with different headjoints. I recommend trying as many as you can and finding the best match. Good luck!