Were it not for the gameplay footage it wouldn't be clear to me if this guy actually played SS2, because he summarized the plot more or less as "the crew of the Von Braun located a distress beacon on Tau Ceti V, landed, brought the eggs and a data wafer they found there on board, then integrated SHODAN into the ship's network, ultimately leading to a repeat of the events of Citadel Station as SHODAN takes over the Von Braun and experiments on humans." The last bit is only true in the loosest possible sense -- SHODAN impersonates one crew member and has one soldier cybernetically enhanced to complete her goals, which include integrating herself into the ship's network (this is not something the crew does willingly on their own).

Also, he confidently asserts that "virtually none of the action games we have today would exist" without System Shock 2, due to its fusion of RPG elements with action-adventure games, even though this hardly a new idea at the time. It goes without saying that Ultima Underworld did this fusion earlier, as did some FPS-RPG hybrids prior to 1999 (Strife, Hexen, Cyber-Mage), and furthermore there was already a strong tradition of mixing action gameplay with RPG character development in Japan in the 90's which almost certainly had more influence than SS2 on action RPGs today. SS2 influenced a number of Western developers, but it's hugely overstated here.

I'm not sure what definition of action RPG you're using if it's predominantly first-person games. Whether or not you think Wikipedia is authoritative on any subject, it provides a wealth of history and citations stating otherwise here (referencing a hefty amount of Japanese games): https://en.wikipedia.org/wiki/Action_role-playing_game

Under any common definition, action RPGs would include Diablo, Gothic, Mount and Blade on the Western side; Secret of Mana, Castlevania Symphony of the Night, Dark Souls, on the Japanese side, to name a very small few. None in first person, and there are plenty more like them.