However for consoles 2000 slices between machines of the same generation like the aforementioned Dreamcast (pre-2000) and Gamecube (post-2000). These are systems that shared groundbreaking titles between them like Phantasy Star Online; which was one of the very first online multiplayer games for consoles (and which I still play weekly guild matches, streamed on Twitch).
After that generation of consoles the specifications for consoles were all pretty similar to PC (chipsets aside): ethernet, wireless, HDMI (the previous generation were all pre-HD too), a HDD, etc. But it was the Dreamcast (and, released much later, the Xbox) in the generation of consoles before that really pioneered this shift in paradigm for console gaming and which many of the consoles of that era only had support for via addons (GC Ethernet Adapter, PS2 Network Adaptor, HDDs for the PS2 Expansion Bay, etc. Heck, even the GC didn't ship with ethernet instead having a dial up modem, and it wasn't even as fast as 56K in most regions!)
Thus I think they deserve to be retro for the same reason that 1996-2000 for PC gaming does: they defined how the next couple of decades of gaming would look while making plenty of mistakes along the way.