Late to the party, but I don't use the term "transsexual" because, unlike "transgender," I feel like it has significantly more potential to be toxic in its usage. The term scares the shit out of me when I encounter a trans woman who identifies with it because my immediate assumption is that she is transmedicalist, enbyphobic, and likely other forms of bigoted as well. Sometimes, truscum push this false dichotomy that basically paints "transsexual" and "non-binary" as mutually exclusive, but even going by their definition of the word "transsexual," I, as someone who definitely is not binary, could be considered transsexual. This shortsightedness comes from the fact that many of them don't know that there are enbies who actually medically transition.

That being said, I know that not everyone who identifies as "transsexual" will be an absolute piece of shit, but it gives me very negative vibes for sure. Based on trauma I've lived through that has burned some of the harshest internalized transphobia into my mind so strongly that it's still not gone to this very day, I have an extreme degree of hatred for transmedicalism, so something that can remind me of their wacky antics like bringing the term "transsexual" back into common usage as a form of separatism from the trans community can be a bit disturbing to me.

Also, I really do not like people making a big deal out of etymology and semantics. There are people even here saying, "I use 'transsexual' because I'm changing my sex and not my gender," which isn't something I'd say is wrong to say, but even then, the terms "sex" and "gender" are rooted in arbitrary constructs with no entirely coherent definition. I don't like to give any merit to the categories of "sex" and "gender" being anything but arbitrary. However, I do think people should identify with terms that make them comfortable, and that's what I believe queer identity should boil down to at the end of the day.

Labels for gender identity and sexual orientation are often just neologisms that you best interpret by using your own personal experience regarding gender and sexuality. Y'know, descriptive and not prescriptive. There was a frustrating time where I'd scroll pages that describe various gender and sexuality microlabels and whatnot, trying to find out which exact definition I found on these sites suits me the best instead of just basically going by vibes, even though "vibes" ultimately ended up proving itself as the best way of teaching me "how" to identify my gender and sexuality. Ironically enough, it makes my identity feel more accurate than it would if I tried to pinpoint an exact obscure term that describes to a T how I experience gender and sexuality.

As far as the issue with etymology goes, I think it's most definitely not so useful to base how you use a term off of etymology, especially if it's a term that's a neologism that's interpreted by personal experience more than anything else. If we say things like "I say 'transsexual' to validate that I'm changing my sex and not my gender," then what's going to stop people from taking the wholly inaccurate "bisexuality is inherently non-binary exclusionary" claim seriously if we hold etymology at such face value? Usually, this just leads to unnecessary, tiring language games that the LGBTQ+ community does not need.

You'd think "Respect people in regards to how they identify, and that's that." would be an easy enough idea for LGBTQ+ people to grasp, but...