So back to the original post. Like most questions here that get asked in BF, the best answer is "it depends."
Whether a gravel bike will perform well as a road bike for you depends on what you want out of a road bike. From what the OP said (assuming he's still here after six pages of typical BF arguing), a gravel bike with a second wheelset seems like a very good option for him. The caveat being I don't know what his group rides are like. If he's struggling to keep up on group rides with an "actual" road bike, perhaps swapping to a gravel bike with road-oriented tires would put him off the pace. Perhaps. And perhaps not.
A gravel bike can sub in as a decent road bike in many circumstances. As can a cross bike. But a dedicated road bike that can't take tires over 25mm really won't serve both purposes.
So - OP - it depends. My opinion is that for me, I could get by with the gravel bike I just built with a second wheelset and be quite happy. But then my "road" bike is actually a cyclocross bike, so what do I know.
Do what works for you (assuming you haven't already), and not what works or doesn't work for someone else here who may have different desires out of a road bike than you do.