It got us Phil Spencer promoted to The Xboss, so in that regard it was a wild success. In terms of sales, no not really. Most importantly in terms of revenue, surely it had to be a success? A lot of games were sold on it, they had to make a killing in services and digital software sales.

The launch stigma was so poisonous, it also resulted in the complete 180 switch in focus and brought us the most consumer friendly approach to the industry that we now have with all games coming to PC, plus we got GamePass, and xCloud.

Still my second favorite console of all time behind the Dreamcast. But will eventually be dethroned by the Series X.

Well, I suppose you're right that Ninty did a much better job of explaining what the Switch is than they did with the Wii U.  

I think the more steady flow of games thing is more just an automatic thing than an overt change at Nintendo.  They were able to retread much of the Wii U stuff, cuz few people played it.  And, going from two systems to one automatically puts all of their studios working on games for one system.  I never heard any credible rumors about Nintendo developing a new dedicated handheld and dedicated console, so I don't have any reason to believe they unified because of the Wii U.  I think they unified them because the market for dedicated handhelds was clearly shrinking.  

Nintendo from 2017-present compared to Nintendo in 2011-2016 is night and day different. Their hardware much more versatile, well designed, and developer-friendly, their marketing is much more savvy, they're generally a lot more in tune with their audience, their major games are more ambitious.

They clearly learned a lot from the Wii U's failings and adjusted accordingly.

I don't see these big changes.  Yes, their hardware is better in many ways.  But, that's it.  Also, they didn't whip the Switch out in 2 years, it took several years of development. So, I don't know how much of that came out of lessons from the Wii U. 

I don't know what marketing changes that you're talking about.  That stuff looks exactly like it has always been, aside from doing a better job of explaining what the hardware is.  I also don't see that they're more in tune with their audience.  They're making the same stuff as always.  Games more ambitious.....if you mean BotW, sure.  But, aside from that, I don't see any major advances.  Their biggest Switch game - Kart - is literally the same game as their biggest Wii U game.  

I would consider Xbox One a success in the end. Bearing in mind it seemingly made a profit and the generation ended with Xbox's future looking brighter. If your barometer is did it grow the Xbox userbase? Then obviously it was a failure. However, a game or movie doesn't have to do as well as the predecessor to be considered a success. The Xbox One console, Gamepass and Xbox Games on PC all appear to have done well enough to keep this Xbox thing going. And again, the future for the brand actually looks better, so I believe Xbox One OVERALL was a success in spite of glaring mistakes.

For the sake of comparison, Vita and Wii U were objective failures. The Vita did so poorly for various reasons that Sony quickly exited the mobile gaming arena.

The Wii U on the other hand is a failure I'm actually glad that happened, because it essentially served as prototype for the Switch. I mean the Wii U was such a disaster that Nintendo left the home console arena. I know some will argue Switch is a home console, but you are wrong if you believe that. It's a mobile console by design first. And frankly, I like Nintendo focusing solely on a mobile device instead of making underwhelming home console specs.

It wasn´t a success sales wise, in the same way as PS3 wasn´t a success, but just as PS3, X1 taught Microsoft a valuable lesson in how you treat your customers and we likely wouldn´t have had GamePass along with Backward compatibility of it wasnåt fr those lessons. So, it was kind of a success long term for the supporters and consumers :).

quite sure the 360 was the console before the series X/S

Wii U crashed and burned almost immediately and development of the Switch took place during its years as the living dead, so I don't see any way its failure could NOT affect the direction they took.

Their marketing now is much less saccharine and kid-oriented and instead primarily aimed at hip young adults, featuring popular music and trendy attractive grownups more than the preteens that dominated Wii U ads.

Mario Odyssey is much more ambitious than 3D World, Kirby and the Forgotten Land and even Star Allies much more so than Rainbow Curse, Mario Maker 2 more than 1, Smash Ultimate more than Smash 4, New Horizons more than Amiibo Festival, Origami King more than Colour Splash, Ring Fit Adventure more than the half-assed Wii Fit U, Age of Calamity more than Hyrule Warriors 1, Retro are now making Metroid Prime 4 compared to a 2D sidescroller on Wii U, etc.

Current Nintendo is nothing at all like Nintendo of the Wii U era.

I just don't see how you can say that. Most of those games were just normal evolution of those series'.  Some of them, such as Mario Maker and Smash, are basically standard sequels that just build on the previous title.  In some cases, they're not really even advancements. They're just more.  

I think you are really stretching here.  

I don't think it's stretch at all. Mario Maker 2 features a much more fully fledged campaign component and more content than its predecessor, and Smash Ultimate brings back every character from every game in the series as well as being the biggest crossover event in gaming history.