I’m pretty sure it’s implied that Doom & Doom II weren’t fully removed from the continuity, though.
IIRC, the original games end with the Doom Marine stuck in hell… Which is also where they found the Doom Slayer. Additionally, despite his background with the Argenta, the Slayer is confirmed to be human in an audio recording; and his Praetor armor is similar enough to the UAC Elite Guard armor that he can upgrade his armor with tokens taken from dead guards.
So… In short, the Slayer might still be the Marine, but with a ton of interstitial backstory that kind of renders his actual origin irrelevant.
I never really thought about their succession of consoles, but to me, seeing them listed like that feels surprisingly additive.
Like, the N64 had analog sticks, and the Gameboy was portable… And people liked both of those, so they released the GameCube, which had analog sticks and a handle, so you could take it to your friend’s house. They followed up with the DS’ touchscreen and the Wii’s motion controls, and when people liked those too, they bundled all of that into the Switch: it has analog sticks, a touchscreen, and motion controls; it’s a handheld and a very portable plug-in console.
But, as they’ve done that, they’ve always pushed the limits of what they could do. As it stands, there’s not much that can be added to the Switch, so they’re releasing an improved version - like they did with the Gameboys Color, Advance, and SP. Essentially, the limiting factor isn’t Nintendo’s ability to innovate, but rather the technology available to them.
Give it a few years for other aspects of technology to advance, and I’m sure they’ll start pushing the envelope again. They’ll probably wait until they can pack an entire console into a VR headset without a bulky battery pack, then release it with something wacky like a charging dock with a built-in projector, or something crazy like that.