I was in my early 20s when the Dreamcast came out. The discussions online and amongst people I knew had a lot to say about the DC and PS2. Storage never once came up that often

It was always polygons. Sega was saying 3M (highly detailed and textured ones) and Sony was saying 66 or some ridiculous shit.

People were just waiting on it

Yes, by the time the PS2 came out DVDs were getting bigger and that definitely pushed a ton of people to get one as their first DVD player, since most were still over $200 so the ps2 was nearly free (fun point, that's how I convinced the lady I needed a ps3 in 2012)

But really it's about the marketing and PS2 hype. No one knew the Saturn existed, and it's largely due to everyone forgetting about them after the complete disaster that the Saturn was in the US