UX writing: When to use "we"?

(Disclaimer: I am a programmer, not a designer, but I care about good design and good language choices.)

In a mobile UX, when guiding the user through a multistage process, is it better to say "We need to do the thing" or "Thing needed"? It seems to me that the active voice "we" is always more wordy, and for some reason sounds slightly pathetic, so I personally prefer the passive form.

I am 90% sure that when the Material Design guidelines came out a few years ago there was a bit in the 'Writing' section about how "we" should generally be avoided. If that guideline ever existed it has since been removed. And when I google the issue I find recent articles arguing in favour of "we"!

What changed? Are there any rules or accepted wisdom for this?