I'm using MY PHONE. Not one supplied by my employer. I have zero interest in the app having access to my dialer, contacts, or texts. VOIP (whether cell or wifi data) should be able to provide a self-contained system to do that without interfering or needing access to my contacts, my text messages in the native or other apps.
If it is WORK communication it should reside in the app, or my work CRM, not in my phone.
When I installed the new Ring Central it absolutely interfered with texts SELECTIVELY!! IT prevented my sending my own email to my friend inside a text in my Google Messenger app on a Samsung Galaxy S8...thus it was examining my outgoing texts and interfering with them. I have proof of this from screen shots where what I sent wasn't received. As soon as I uninstalled the RC App it functioned normally. Obviously, that doesn't bode well for confidence in an app, or the company behind it. Once you break trust, it is hard to recapture.
I've noticed no such problem with RC Phone - but again, who would know what data it is gathering with broad permissions. Now RC Phone is being discontinued, and I'm not interested in installing the RC app...
I want a stand alone, self contained VOIP app (like many on the app store) that doesn't need access to any other part of my phone than the data to support the features. Period, end of story. I shouldn't have to buy a separate work phone to keep work separate.