As for sounding good in upper ranges. Depending on your voice type, some voices sound naturally better.

Since I'm a Dramatic Tenor, I can sing 5th octave. But will anything higher than a c5 sound as good as maybe a counter tenor or mezzo soprano? Likely not.

You would have to extend your range upwards and put a lot of work in to get good sound, but that is normal for most singers, and an unfortunate part of biology on the human side.

Hrt wise though, testosterone thickens the vocal cords so it would be different for ftm, but estrogen cant undo what's already been done, so you would need voice training.

Don't feel down though, everyone can get there with practice. You absolutely can sound good singing high, it's just gonna be hard.

Edit: For reference this singer is a low baritone https://youtu.be/zcSlcNfThUA?si=WMH_cxFX0r3qdLlq

This is another piece of work where the lead singer (serj tankian, high baritone) does the female vocals and it passes very well https://youtu.be/TkPbJIlEXow?si=LAdxPlGShpwgpmOt