There’s an art to it, which I’ve seen best discussed here, but if you do cold emails well then yes people do in fact agree to such calls. I’ve had ~30% hit rates on cold calls to Berkeley professors while being a Berkeley undergrad in a completely different field, and that was for asks to chat about Zika. I’d expect a higher hit rate for professors in the same field you are in, where you can demonstrate greater understanding than I was able to at the time.
There’s an art to it, which I’ve seen best discussed here, but if you do cold emails well then yes people do in fact agree to such calls. I’ve had ~30% hit rates on cold calls to Berkeley professors while being a Berkeley undergrad in a completely different field, and that was for asks to chat about Zika. I’d expect a higher hit rate for professors in the same field you are in, where you can demonstrate greater understanding than I was able to at the time.