I think this is at the core of most of the issues and the "schism" between older folks from all parts of the ideological spectrum and younger ones.
Old leftist ideas were often of the view that all are equal and should feel solidarity because people are defined by what they do, their skills, their impact - things that produce an observable result external to the individual, so to speak, rather than the color of their skin or who they want to bed. Consequently, discriminating against someone based on these factors is absurd and somewhat reprehensible - akin to discriminating because they happen to dislike the taste of cilantro, something dictated solely by genes - who they are - rather than what they do.
I'd argue that these old leftists would be more likely to scoff at defining yourself via immutable aspects that you didn't choose, produce or earn (like national pride, which fx. a fat unaccomplished retard like Ethan Ralph can invoke to feel proud about).
With the current era of identity politics and (far-left) zoomers it seems especially, there is now a greater focus on people being defined by things supposedly inherent to them - who they want, or don't want to fuck, their mental illnesses, their heritage/skin color. It's utterly bonkers to me, to wish to be defined primarily by things you have no control over and don't impact or are of any use to others, but when you're really just projecting and partially living a kind of persona on the internet, a medium where for the most part, you can't actually produce something independently observable (in contrast to what I tried to describe as impact or external to the individual in the first paragraph), I guess it makes more sense.
It's why I have a hard time grasping dysphoria or phoria or these crisis of identity relating to who one is (rather than what one should be doing). If I woke up tomorrow a woman of any skin color, very little about what defines me would change in my self-perception - I'd just have to adjust my work outs and buy new underwear I guess.
From an externally focused viewpoint, the pronoun shtick also makes no sense - the point of being addressed by a pronoun is to ensure that others can clearly refer to you, so one's pronouns don't really matter as long as you know you are being addressed or referred to.
On the flipside, if you think you are really defined by you yourself and not the world as it interacts with you (because you are a terminally online shut in), suddenly pronouns become important, because they are a core aspect of the persona/identity you project.
