I'm really not with you here. My posts have been written under the assumption that we were discussing what we considered an advanced dive. If the topic was the full scope of 'advanced approaches', I'm off-topic and my posts can be ignored. 'Advanced approaches' is something I don't have a good definition of, so I won't try to discuss it.
I simply believe that it is better to catagorize the
diver, and most relevantly, their approach to a given dive; rather than try to create some 'catch all' definition of a
dive.
Attributing 'advanced' factors to a dive site is quite implausible. You dive in Northern Europe... what is 'basic' for you would be incredibly 'advanced' for a comparably experienced diver who dove the tropics. What you consider 'complex' might seem extremely undemanding and simple for a diver of higher level. So on, and so forth...
So...a dive site, or location, may demand an 'advanced approach'. That'd include specialist skills, protocols or equipment for sure... but relative to what? Also, shouldn't we also consider the application of specialist skills, protocols and equipment on seemingly 'basic' dives? Just because a site is benign, doesn't mean that safety cannot be improved by the diver's approach to the dive.
It'd be fair to designate a site as 'basic' - but that still has to be attributed towards a specific level of training/diving. For instance, a 'basic' open-water site... or a 'basic decompression dive'... or a 'basic' wreck penetration. That leaves us with an understanding that an 'advanced' site/dive requires something beyond the bare qualification-level essentials... some accumulation of further generic or specific experience, some specialist competencies etc etc
That's an 'approach-orientated' perspective to defining the demands of a dive.