I'm afraid Opera could lose market shares to Microsoft if MS should succeed in developing a browser with a nice UI and some useful additional features.
For myself it has proven quite hard to shift me from whatever has been my preferred browser. I was a Firefox user for well over a decade. I've now switched to Opera as default (although I still use Firefox). Edge will have to replicate the features of Opera that I've discovered to be compelling to get me to switch.
I should say though that I do not find any one browser to be superior to all other in all respects. Hence I have several installed and occasionally have a need to use one of the others - even Edge as it happens!