It's probably a personal preference, but in day to day usage 2x zoom seems to be a lot more useful to me than 3x zoom. I use the 2x zoom all the time, but I rarely feel the need to zoom in more than that.
I realize that this issue is really a side one compared to what is being deeply discussed in this thread...but I wanted to chime in on this one. I think I have a skewed perspective on this. I'm sitting at my desk, and to my left, about eight feet away, is a sliding glass door out onto my deck. And then another ten or so feet away is my bank of bird feeders; add another four feet, say, for the one that is furthest extended. I shoot out there all day from where I'm sitting, as best I can, which, you know, birds sometimes don't stand still, lol. Sometimes, to keep from startling the birds, I will retreat even further away into the shadows of the kitchen.
My phone has never been adequate to the task. I currently have a 13 mini, which has no telephoto, but I do have an added 2x external Sandmarc lens I've tried, and it really doesn't pull things closer enough. If I want to zoom in on a subject after taking the photo, I really have no chance at all of getting anything clean or recognizable. I don't think 3x would be sufficient, but it would be better at least. I currently shoot with my DSLR (nothing that fancy, a Canon Rebel T2i with a kit zoom lens), and I get much much better shots.
Now, this is really a specialized case, sure, and I bet I won't have to look far to find opinions that phone cameras of any kind are really not effective for wildlife photography anyway, at least not without a lot of added equipment. But going through this exercise validates my decision to just get the 13 mini and not worry about missing out yet on what the pro line gives me camera-wise.