It's a little strange to read accounts like this. I've been using Voice continuously for years now, and ported my old number into it. There were a few years when it kinda sucked (yes, I also lost group/mms messages with no warning), but since the integration with Hangouts (2014? 2015?), I've been quite happy with it again: group messages work, pictures in messages work, etc. Hangouts isn't perfect and still has lots of missing features and annoyances, but it's been overall acceptable to me.

I do have two unusual situations that make Voice a good fit for me: I don't have reliable cell reception in my apartment (so texting and calling through wifi is really useful), and I'm on the T-Mobile $30 plan, so I have only 100 minutes on my "real" phone number (so I make as many calls as possible through gmail on my laptop). It's also really nice to use my regular phone number with no extra effort or roaming fees when traveling internationally.