I've been using GV for over a decade. It's the last Google service that I still use regularly. I use mailinabox for my email/contacts/calendar/drive. I've looked, and there aren't any drop-in substitutes for GV. I've had a Number Barn account with two phone numbers for a few years. They seem to provide better voice quality than most alternatives, but their SMS integration is poor. I'm not sure if they even do voicemail, but I don't think they do.