All 8th gen systems, Scorpio, Pro and Seitch are all mid gen refreshes with the same goal in mind: increase sales, maintain competitiveness.
Pro is the smallest upgrade, since PS4 is already a great product and will continue to dominate sales, so a big change is t needed, and affordability can be put ahead of low profit margin headline grabbing.
Scorpio is the biggest, because the XO isn't failing but it is struggling, and MS has neither the first party strength nor industry wide influence to compete on exclussives, so throwing as much hardware welly behind multiplatform third party titles is their best bet at improving their market share, while also keeping their early XO adopters in the mix with a fully shared software library.
And finally, the Switch is trying to reinvent the wheel, consolidate Nintendo's wider (but declining, and thus also in need of shoring up) handheld market, while trying to distance themselves from the WiiU as much as possible. As such they've tossed their first attempt at an 8th gen system under a bus, and rather than a continuous library across the two consoles, select games are instead getting ported over. However unlike the other two systems that are attempting to expand an already healthy install base with a premium product, the Switch is coming back in at the entry level, and even then, may have undershot the basic minimum specs, and this could well bite them in the arse if they can't get all the vital third party releases that define console gaming.
Either way, they're all 6 8th gen consoles, base models, upgrades and second attempts, all are fundamentally part of the same industry wide standard, and simply releasing a new system with the same games or comparable hardware doesn't change that.
I get what you are saying, but I wouldnt call the Switch a mid gen refresh. Pretty sure Nintendo doesnt look at it like that either.
Since the Wii U has been discontinued.