Thanks for engaging and looking at those examples, you do see a bit of what stands to be lost from the requirement of completing a city if that change is made. Reading your response I felt like I was kind of winning you over until the third paragraph, your impetus for beginning CityStrides - I still contend that this raison d’etre for the site can evolve and elaborate over time, as have so many other aspects of this platform due to your own hard work and input from users such as myself! There is a focus in your and @davemorin’s replies here on street count and effect on street count…I honestly have come to care a lot less about that. To me, CityStrides is a framework to encourage the user to complete their city, confined by the definitional limits of OpenStreetMap. I love reading the articles other users have posted when they get interviewed about completing their city in the media, hearing the little details about what they learned and discovered during their (usually years-long) journey.
So there’s the coding/technical aspect of building out the CityStrides platform, and the philosophical aspect of what it is and how to use it. Philosophically, I think more narrowly defining what is a road or street reduces the city, reduces the challenge, reduces the incentive to explore. Therefore, technically, I feel we should be including more named way relations in the CityStride street list. Road, street, avenue, etc. have discrete definitions but the landscape around them may have evolved in the decades or centuries since they first were named. In fact, that concept spurred me to pause this response yesterday and write another semi-tangential post: Atlas of road types in Portugal, a guide
If I had my way, the named way types currently excluded on OSM that I’d add are alleys (this one being out truly mystifies me), [public] driveways, paths, foot paths, and steps, and keep pedestrian areas of course. My criteria for exclusion would be strictly safety (no highways, tunnels, etc.). But I’m not in charge, so I’ll keep on exploring my surroundings in the way I like, and I’m always grateful to you and CityStrides for starting me on this semi-obsessive adventure. And I know from posting here over the years that there are other striders like me who prioritize painting their map as purple as possible 
Just want to reiterate my appreciation for the good faith engagement from both of you despite our differing of opinions. Cheers