The one gap that smartphones still have is depth of field versatility, which is a function contingent on focal depth and it's impossible to build into tiny cameras.

Having said that, depth of field versatility is only one tool, and often it's a hindrance rather than a help (e.g. we're trying to find the hyperfocal depth and maximize depth of field). For a wide gamut of photography realms such as landscape photography, city life, etc, it is absolutely true that a modern smartphone can compete with any SLR and create perfect results.