I think Wii U is a lot more like the Saturn. Because it was broadly unappreciated in its time by the masses (for good reasons in both cases), its fans are evangelists now for every hidden gem on the system, and everything it did well.
So yeah, playing Vampire Saviour and Battle Garegga on Saturn were and are great. VF2 is probably the best game in the genre in the generation etc. But back then, would you really have been happy playing only Xmen vs Street Fighter, while PSX/N64 people got Banjo Kazooie, Metal Gear Solid and Ocarina of Time?
I wouldn't really make much of a comparison between the Wii U and Saturn either tbh, and a lot of it would be for the same reasons. The Saturn had it
rough in direct comparison with the PS1, but it actually wasn't software starved at all until the later years. For the first two years of its life it had pretty damn reliable third-party support from almost every publisher barring those like Square, Namco and Konami that had aligned themselves closely to Sony. It still got a lot of the big IPs that were formed that generation like WipEout, Resident Evil, Tomb Raider (and crap like Battle Arena Toshiden), etc even if it lost that support from about late 1997 onwards. The main differences I say between the Dreamcast and the Saturn was that the Dreamcast died young, whilst the Saturn lived long enough to have a miserable old age. Clinging to releases like X-Men vs Street Fighter (which you had to import) or Panzer Dragoon Saga really happened only after the console had effectively been killed by the PS1 and later introduction of the N64. It's not like the Wii U where it suffered a lack of releases throughout its life. The Saturn for example also has pretty decent genre representation across most genres (better than N64 in many ways), whilst the Wii U struggles badly in that regards, with there often being only a couple of significant release in numerous genres. The fact that the Saturn was actually considered a success in Japan also gives it library additional depth, as it stacks up surprisingly well against even the PS1 in hindsight for those types of games.
And, same with the Dreamcast, the Saturn's lineup of notable games wasn't basically a Genesis+. It has some (typically not very notable) representation from some IPs that were familiar names like Thunder Force, Shinobi, Golden Axe, and (to very limited extent) Sonic... but the vast majority of games that would make someone's recommended list of Saturn games didn't exist the prior generation. The Genesis didn't have a Sega Rally, Daytona Virtua Fighter (besides the later down-port of VF2), Virtua Cop, NiGHTS, Panzer Dragoon, Burning Rangers, Virtua Cop, House of the Dead, Last Bronx, Die Hard Arcade, Virtual-On, Guardian Heroes, Radiant Silvergun, etc... these were all brand new experiences, not just the latest instalments in IPs that had been around for a decade or more. And in regards to legacy, the Dreamcast didn't get to work immediately looking to obsolete a bunch of them. I don't think people will look back on the Wii U as a treasure trove of games that went unappreciated. In a decade if you want to play Mario Kart, you'll either just be playing Mario Kart 13 or whatever we're up to... or you'd pull out the Switch for Mario Kart 8 Deluxe. This is likely to be the case for Zelda BOTW, Bayonetta 2, Smash Bros, Splatoon, NSMB and a lot of other Wii U games, which diminishes a library that was already sparse to begin with.