*What do you think trans people existing looks like?
If we treat Transwomen exactly like men, and Transmen exactly like women... How is that any different from saying they don't exist?*
Presenting in a way that makes them feel like the opposite sex based on stereotypes, such as men wearing dresses, skirts, make up. Transmen remove their brests, cut their hair short, take testosterone. All that is fine if they so wish and shouldn't be treated adversely as a result. All power to them. They should be free of discrimination.
It doesn't mean they get to go into spaces of the opposite sex and noone else has to be compelled into believing someone else's pseudo version of reality, if they don't want to. It's not the same as saying 'oh you can't enter a shop because you are trans, or get on a bus etc' that is discrimination and saying they shouldn't exist.
There are clear distinctions.