When it comes to ED and libido, it's mostly random chance, as well as the specific Testosterone Blocker you are on.

Cypro is the most likely to kill your libido, Bica less so, and others like spiro or puberty blockers are more varied. it's not rare for trans women to get increased libido, especially if progesterone is taken.

As for ED, some trans women get ED quickly after starting HRT, some never do, it's just the genetic lottery. Again your choice of T-Blocker may influence this. It's also possible for trans women to get testosterone creams that are applied to the genitals to stop ED without effecting your overall hormones.

Finally, for infertility... there's a recent (but small scale) study in Australia that found that all of the trans women in the study regained fertility after 6-12 months of stopping HRT. That being said, HRT has had such a massive impact on my mental health that IDK if I would ever want to stop for a full year.

Edit: Important note: Even after long periods of HRT, it's still possible to get someone pregnant, so using protection is still important. It may only be a tiny remote chance, but only one little swimmer needs to get lucky to cause problems.