It's a few things that piled up, until, I felt the trans side was irredeemable and sucking all the oxygen out of the room. I'll list them in no particular order:
1. Making your gender my problem. If you're an adult, then it's your prerogative to do what you want with your body, but I don't want to join marches and demonstrations about what public toilet you use or whether you can
compete against natal women in swimming cause you couldn't cut it in the men's div. These are not problems real women need to worry about; we have bigger problems to deal with than whether you can play chess professionally in your gender of choice. These are 1% problems in the sense that 1% of the nation (or less) is trans, but their desire to (checks notes)
powerlift at a competitive level is more important than say, abortion rights.
2. Gender in lieu of personality. I swear that half or more of these people yeeted their personalities along with their secondary sex characteristics. Example: Contrapoints absolutely jumped the shark after coming out; what used to be an amusing channel of 15-to-20 minute videos about topical philosophy metastasized into 2 hour long biopics of Nick/Natalie admiring his own reflection. If a natal woman behaved like that, she'd get railroaded as a THOT and a whore and a fake, but when Contra (or other trans YT hoes) do it and it's suddenly visionary art worth thousands a month.
3. Memory Hole. Continuing on my Contra examples, Nick deleted all of his early videos and only kept the more recent 2-hour snoozers. Unfortunately, lots of trans people do that, and basically expect you to pretend that the first 20 years or so of their lives either never happened, or that they were retroactively the opposite sex the entire time. It's like ret-conning your fanfic, except it's your life, and you expect everyone you know to just play along. Proactively it gets even more retarded; with TRAs insisting that it's typically masculine to get pregnant and give birth and typically feminine to (

) father children with a natal woman. It's like the story "The Emperor's New Clothes".
4. The insanely risky behavior. I seriously hear and read stories about MtFs and FtMs in their teens meeting up with dudes twice their age or older on Grindr. And then they're surprised when they end up getting pregnant/an STI/murdered and act as if this is some personal affront rather than the result of getting drunk at fag bars and going home with whichever guy affirms your gender the hardest. These idiots also go abroad for major surgery on their dicks and then act shocked that they have complications. No shit, don't get your SRS done in Mexico!
5. The class whining. Being trans and having a plastic surgery addiction is basically a circle diagram, so trans men and women feel it is a matter of life and death that they get expensive hormones and blockers for the rest of their natural lives, in addition to a series of invasive plastic surgeries with a high incidence of complication. Only in TRA Genderland is it reasonable to demand your health insurance / the government should cover allthis bullshit. The result is that we get high-end whining out of people like Oliver Thorne about how the NHS is LITERALLY KILLING HIM by not scheduling his dickectomy ahead of everyone else in the UK who have real health problems requiring surgery (not made-up gender problems). And since TRAs are almost universally poor-as-shit internet scum, they have this aggrieved class anxiety that manifests as salt rage towards anyone who isn't blowing their whole paycheck on manicures and waxing.
6. Rigid gender roles. TRAs loooove to suggest that any girl who isn't stereotypically "girly" or any boy who isn't the captain of the football team is a potential gender skinwalker ready to be converted to the Holy Faith of Being Trans. It's really tiresome to be told by some dude dressed like a woman that I'm insufficiently feminine and he's beating me at being a woman. Not that I'm going to play feminization olympics with a mentally ill person, but I also don't like being looked down upon by them or force-teamed into defending their god-given right to wear makeup that makes them look like Mimi from "The Drew Carey Show".
7. The kids. If my kid were to say she was actually always a boy and I needed to give her testosterone or she'd kill herself, I'm taking her to a fucking psychiatrist to figure out what her damage is. There is no reason to fast track teenagers into making medical desicions that have lifetime consequences. (please recall: teenagers are famously terrible at understanding long-term consequences of anything they do.) Almost universally these youth transitioners do nothing to bank their germ cells, so they end up sterile and crying about it decades later.
I think that's all, but I may add more in a future post if I think of other stuff troons do that really grinds my gears.