Currently, everyone uses Zoom across my company. We use it to communicate easily across teams and locations. I work 50% remotely so Zoom is absolutely necessary to participate in HQ meetings. The connection is very reliable and I trust it with my meetings that span over 25 people for hours at a time.
Google Hangouts is more easily integrated into Gmail, but I have found that the quality with Zoom is much better. However, I have noticed times when bandwidth requirements seem lower with Google Hangouts - making it my go-to when I am somewhere with an unreliable connection. I also think Google Hangouts makes it harder to share exactly what you want.
Zoom is perfect for intimate business meetings or professional 1-on-1s. I have found that if I quickly want to instigate a meeting through Slack, I can do so directly by pasting a URL. However, I have found that setting up for a large room can prove tricky especially since my office installed OWL accessories.