I'm currently in an N=1 state but I've come to the realization that the perfect number of bikes for me would be N=2. I have a steel gravel grinder with two pairs of tyres that I use for everything, but it has a couple of downsides (no backup bike when it's on repairs, a pain to change pedals when I don't feel like wearing my spd shoes, etc). I'd be happy with my do it all road bike + a hybrid bike, but don't have the space ):

The Specialized Diverge sounds like it could be a good N=1 bike for OP.