As I said, the video is about general types of SSDs, not specific games. It's also mixed between first load after launch, reload of a save and sometimes fast travel, no real methodology.
When the game uses DirectStorage, a PCIe SSD will be a lot faster than SATA or HDDs. Games like Last of Us Part 2, Spider-Man 2 or Ratchet & Clank were shown. Indiana Jones doesn't use DirectStorage, but still shows this kind of behavior.
Without DirectStorage, it mostly doesn't matter, as long as it's an SSD, although PCIe drives were almost always faster. If you reload a save, a lot of time, it often also doesn't matter if you use an HDD, although you might still get the glitches and pop-ins from slow asset streaming.
Here's a list of Steam games, that use DirectStorage. It's not a lot right now, so you definitely don't need to switch right this second, especially if you already have a SATA SSD, and you're not playing the latest AAA games constantly. It is something to keep in mind, when you're upgrading though.
Bought Titan Quest 2 in Early Access and played through the current content (Prologue + Act 1) with two characters.
While the game is fun, the current masteries (classes) are kinda boring (except Storm). For some reason, only the Storm mastery gets different basic abilities (low cost, spammable attacks), and everyone else is stuck with the dinky basic weapon attack. I also wasn't too hot on the active abilities for the Rogue and Warfare mastery, so I basically just ran around with two passives and the default attack otherwise (which you can upgrade) on my Bowman. My first character, a Frost caster (Storm+Earth mastery) was a lot more fun, with better abilities.
I wouldn't recommend at its current non-sale price, but it's a good foundation, as long as the devs can keep updating the game with more stuff.