The collapse was almost vertical and did occur in a very tight footprint, so that part of the assertion is barely an exaggeration.
I'm seeing wreckage and damage to all adjacent buildings at least a block in most directions other than lower right, you can also see the "footprint" goes up and left :
The buildings were essentially hollow tubes (the structural exterior) connected to a core by the trusses supporting each floor (the whole point was to have huge expanses of office space unbroken by support columns). When the floor trusses failed due to increased load and the fires, the floors started to pancake, which left the exterior and core without mutual support. There was nothing to apply lateral forces to the collapse, especially below the impact zones, so gravity brought it almost straight down.
A more traditional construction would not have likely failed in this way, because whole floors aren't normally suspended like they are in framed tube architecture. If an impact and/or fire had caused localized damage severe enough to precipitate a collapse the rest of the structure would probably be pulled in that direction because they aren't held together by relatively flimsy floor trusses that would already have been stripped from vertical support structures.
Anyway, the argument that other buildings haven't failed the way the WTCs did is, if anything, support for the official story because the WTCs were of radically different design to most any collapse or major fire conspiracy theorists refer to. If it had looked similar to anything else, that would have been really weird.
Its almost like very tall buildings are specifically designed to be capable of being demolished without wrecking half the city centre. Any video you pick that shows more of the buildings themselves shows uneven collapse, watching it unfold in real time from news archives even more so.
Which is why conspiracy theorists stick to one that only shows a few seconds of a building falling out of view, its not so much a smoking gun as it is deliberately concealing inconvenient facts.