Sega Saturn was the system that failed when Sega needed them the most. That was right when gaming was going to stop being "a toy" and become much more mainstream.
Sega needed a console that outputted 3D graphics, played the most of their popular arcade games, and brought their previous franchises into the third dimension, that was reasonably priced. What they got instead was a system that was a 2D powerhouse but was in practice horrible for 3D, played niche arcade games from other companies that nobody cared about, and didn't even migrate Sonic the Hedgehog, let alone their other franchises to the third dimension or even on the console at all.
Sega fixed almost all of this with the Dreamcast but it was too late. The console market already was established and Sony stole their audience. Contrary to popular belief the Sega Dreamcast was making some headway in the holiday of 2000 and even beyond, but Sega simply ran out of money to support it. If Sega launched a Dreamcast equivalent in the Saturn's place Sega could possibly be making consoles to this day.
The Wii U was also a disaster as it failed to answer the giant elephant in the room which was "what will Nintendo do now to keep up people's interest that the casual audience have ditched the Wii and handhelds?" To make things worse Nintendo also launched the Wii U in an awkward date, making the successor having to launch in the middle of the generation. Nintendo, being Nintendo, decided to take their lemons and make lemonade by making a hybrid console that could have its cake and eat it too.
That said, Nintendo had the time and money to make that R&D as while they were bleeding money during the Wii U era, it was just that...bleeding. Sega in contrast was gushing out blood from all of its limbs in debt. And a lot of that had to do with the failure of the Saturn and their arcades no longer being successful enough to cushion their blow.
Another reason I reckon this equivalency doesn't work is the financial size of the companies, even at the respective times. I can't find specific data for Sega at the time, but in 2014 -- in the midst of the Wii U's struggles -- Nintendo still had
$14 billion in liquid currency. I remember it being reported back then that the company could sustain the type of losses it took for that year or two (out of its, at the time, 125-year history) for something like 50 consecutive years before it had to start selling assets.
Again, I don't know what Sega was working with circa 1995, but I think it's safe to assume the company was in nowhere near as good a position to sustain a failure as Nintendo, let alone the string of failures leading up to the Saturn. It's hard to compare a one-time market failure from a larger company -- who had a simultaneously successful hardware on the market, and even managed profitability during the Wii U era -- to a sustained streak of market failures from a smaller company.
This just highlights how timing mattered. When the Wii U hit, Nintendo was massive company thanks to being relevant throughout all gaming consoles to that point. Including the massive growth gaming had during the latter half of the 90s. Sega completely dropped the ball right when the market was about to explode, and tried to break back through after the market had grown so much. Yes the Dreamcast lost a lot of money, but if you want to go back after the 16-35 year old male market that was necessary. I mean look what Microsoft had to do just to make a DENT into the PS2 just in America. And again, the Dreamcast WAS technically not sinking anymore in January 2001. But Sega ran out of money. The Dreamcast sold more than the Wii U adjusted for dates as well if I recall, and that isn't taking into account of world population differences between the periods.