Let’s take a step back. I don’t think we need to decide here whether individual streets can have names. Everyone participating in this thread so far hails from a country where they generally do have names. We also don’t need to decide whether there’s a notion of a highway route separate from the notion of a road or street. That has been proven many times over by mappers and data consumers. Trails can get a bit fuzzier because they often aren’t as systematic as roads in many respects. We can try to hash out a consensus about them, but I think it probably deserves a separate thread.
Aside from any routing aspects, what is a street, and how do you delineate it? One very common way to delineate a street is to look for the (mostly) contiguous roadways that share the same name, modulo the occasional directional prefix. But a street is more than a name, as the Wikipedia articles demonstrate: it has an identity that may be bound to a long and storied history, all worth documenting outside of OSM. OSM benefits when there’s some link to those external projects in one direction or the other. We can tag individual roadways with their wikidata=* tags, but some mappers have attempted to refactor them into a single coherent relation, following the mantra of “one feature, one OSM element”.
Now take the paragraph I just wrote and replace “street” with “waterway”. There’s still a lot of uncertainty about how to delineate a waterway, but no one argues for the abolition of waterway relations. In some regions – maybe not Western Australia – there are even more waterways than streets, but we take a pragmatic approach, sometimes creating waterway relations and sometimes just tagging wikidata=* etc. on individual waterways.
Now take that paragraph and replace “street” with “railway”. Rail mappers have to keep multiple concepts in their head at the same time: the physical trackage on the ground, the railway line as a system, and any services in operation along the line. Some countries even distinguish between route=railway and route=tracks. This goes right over my head. Rail mappers probably get away with this degree of highly technical structure because the rest of us manage to ignore rails except at crossings.
Do either of these precedents inform whether there should be street relations and, if so, how they should be tagged?