Jillaine, I should probably have clarified a little more about why I prefer to keep WikiTree stuff on WIkiTree (I mean, besides what I said earlier about the possibility of what I like to call the "accumulated wisdom" of the group becoming unavailable due to whatever problems might occur on the other site):
In my case, I don't use Google anything, because my real job entails me having extremely sensitive information on my computer, and Google just doesn't "get" the concept of privacy. So I'm excluded from any discussions that happen on Google services, not due to lack of interest on my part, but because I can't let what is, after all, only a hobby (at least for me) override the responsibility I have to keep other people's information private. Up to now, I have joined projects which encourage the use of Google discussions among project members, but just haven't taken part in the discussions on Google. (And, no, I'm not happy about that situation, but that was the compromise I came up with.) Maybe it would be better for me simply to drop out of any project which uses Google for discussion.
Facebook has a similar problem with lack of respect for people's privacy, combined with getting more and more annoying. I still like the concept of a nearly effortless method of keeping in touch with friends and family, but one day a couple of years ago, my feed had more spam and political ranting (despite my best efforts to filter out sources of both) than updates from any of my friends on what was going on in their lives (by a ratio of at least 4:1), and that was the proverbial straw that broke the camel's back. I closed my account a few days later (after warning my friends that I was planning to do so) and haven't looked back.
I was kind of amused, after the Cambridge Analytica scandal broke, to read columns in the tech press, in response to various people's calls to drop Facebook, arguing "You can't quit Facebook, it's too much a part of your life." My response to that would have been "Oh, yeah? Watch me!" if I hadn't already been off Facebook for months at that point. I do miss being able to keep in touch with friends and family so easily, but I don't miss Facebook itself even one tiny little bit. But then again, I never was one to follow the crowd.
Now, I probably spend more time on WikiTree than on any other site (other than the ones I use for work), although I am on a couple of other sites that, like WikiTree, I would classify as at least partially social networking.