As pilots we use a combination of factors to ensure the aircraft is on the correct approach path. Some of these include thrust setting vs rate of descent, three x height, GS, DME, position of rwy threshold on windscreen, all backed up by the PAPI.
Visual aids should not be used below 200ft anyway.
If the aircraft was not stabilised by 1000ft - 500ft agl it should have gone around but if this was a low level windshear issue the availability of either Vasi s or papi is irrelevant.
Half the airports we flew to at night back in the eighties had neither.