I am always grateful when people put their pronouns - saves me googling the Kims and Sams - I recently chatted to a customer service person with a VERY traditionally female name (at least in German) who did NOT have their pronouns in their (follow up) email and had to first name them, since I couldn't be sure that baritone had been a man (I googled it - that German women's name is a man's name in Eastern Europe, like Simone and Andrea are men's names in Italy).
Pronouns are clarity and convenience.
See, this exactly why I don't get the need for declared pronouns.
I've worked in international contexts for years and as you say, it's very common to not know someone's sex from their name. But I've never had a problem doing my job and have managed not to cause offence by assuming that a person could be either sex until I actually know.
It's perfectly normal for me to say "your colleague Xien" or "Taylor asked me to give you a call" and then to keep things neutral until someone who knows them confirms which pronouns are suitable. I have never known it to be an issue in a business context - as long as you don't assume, you just get in with your job as usual until you have more information.
I can see why someone might prefer to declare their pronouns in advance if they're upset by being misgendered, and that's obviously up to them.
But even with colleagues who are non-binary, if someone else refers to them as "she" in a meeting, it's quite easy to say "actually, Tan prefers 'they'" or to make a point of modelling Tan's preferred pronoun in your reply, if that's what they've requested.
I absolutely see how this has evolved from LGBT allies initiatives (similar to heterosexual staff putting rainbow flags on their desks to show it's a safe space to talk about your weekend plans with your same-sex partner without jeopardising your promotion prospects).
But there's being an ally and there's being sucked completely into someone else's belief system without your consent. Which is exactly what forced declaration of pronouns is.