I wouldn't say writing Hubs has caused any "significant life changes" for me, but it HAS accomplished a few things:
1. After 3 1/2 years of Hubbing, I finally started earning enough this year to pay for our monthly satellite Internet hookup fee.
2. Just this month, I suspect in response to now having my pages in a subdomain, views and earnings have both skyrocketed. Daily view count has more than doubled, and earnings look like they may be on the way to quadrupling. Too soon to be sure, but looking promising.
3. Yes, I have met some new friends, and good ones at that.
4. Writing at HP has given me a political voice, a megaphone I never had before. The direction this country has been headed for some years now has had me alarmed for literally decades. I've been intermittently politically active--but never as EFFECTIVE as I've been since my HubPages-backed articles began finding top-ranked slots on the search engines.
So: Has all this changed my life? No. But it has made it more productive.