But my point is that in most cases it's irrelevant and it isn't something everyone has to start doing.

I did not yet see this happening IRL, but I can see that just exclaiming it is not appropriate. Though maybe they honestly just don't know what better way is there to introduce themselves, and to be clear, I don't know either.

When I go outside and look around me, 99% of the people don't need to tell me what their pronouns are, because

Because you won't have to do anything with them. They don't tell their name either, because why would they do that, when just passing by on the street?
However at introductions there is a place for the pronouns, however weird it sounds today. I mean, introduction is about letting others know you and your things that you find relatively important.

but in reality most people don't want to tell you their pronouns,

Never said anyone would have to. I would never do that either, because is it obvious. Same for most people, because it is obvious. This is an optional thing, even for non-binary people: only those have to tell it who want to do so.