I am 100% confident it's them because so many details lined up (team, size of family, compensation, role, location, job level) including them using a specific phrase of words after a few days I sent it in our work chat

Obviously, I can't prove it's them so HR would never take action. Not only that but this guy is one of those started coding when they were 10 years old so not only are they a higher level than me, they also perform way better than me so complaining to my manager or teammates would 100% also backfire as they would 100% prefer a very high performing misogynist and transphobe than a poor performing woke sjw (me)