@vshah2
It depends on the scenario! Many people confuse "enterprise grade" with "real time". PowerApps is a platform to create no-code apps. It is VERY cloud oriented. And as many know with cloud activity, it is not always so real-time.
And it also depends on how it is looked at. If developers are giving it the stink-eye, this is mostly because PowerApps can do some awesome things without any code. Bean counters like it more because you can generate some awesome apps in a fraction of the time and cost of traditional development work.
Anyway...there are a lot of articles out there that market PowerApps which are based on enterprises. You can start with the customer stories.
But, to really nail that claim (without any proof - which I would say, there is proof it is enterprise grade, provide proof that it is not!) it depends on the scenario. I wouldn't use PowerApps to manage a nuclear power plant reactor control, but I would use it just about everywhere else dealing with processes and automation within the power plant.
My $0.02. I hope it is helpful.