^ Which part? Are you referring to the multiple manufacturers, the high cost, short console life span, or lack of exclusives? Most of the consoles you mentioned (along with the Pippin) failed for different reasons, though cost and poor games usually were the most common reasons.
Different manufactures. It just does not work. Different standards each time and makes for repairs to be a nightmare and it confuses consumers. There is a good reason why the ones around now have a standard. Steam Machines are a massive failure as well. Saturn was loaded with games but difficult hardware and bad marketing in the USA. In Japan you had many models and while SS was a success in Japan The Hitachi Saturn and JVC saturn were really dumb.
There is one potential difference: a Xbox console would be running Windows 10 and use standard hardware.
I think that all Microsoft would do is add 10-foot interface components to go with the tablet and desktop interface components, then treat all consoles as a standard PC with HTPC elements. I believe gaming enthusiasts would be able to build their own consoles from scratch - like when they make their HTPC - then just buy a Windows 10 license and plug in a controller. I can see Xbox features like chat becoming standard Windows 10 apps, and having games purchasable from the Windows Store.
This would allow for people to use PC sticks with the Xbox interface, and play Xbox games on systems that support it. I suppose Microsoft would set powerful minimum requirements for the consoles, and force companies to meet power and driver requirements to be certified as a Xbox console.
But it is doable, and would work far better than a bunch of similar black-box systems with mysterious and nearly identical innards.
I think the console gravy train is going to keep going as long as possible. I am not sure how long it will take before we see bigger gaps in distance between them being produced, but it really all just depends on the rate that new tech is distributed and made more affordable. We have single-atom material to work on and incorporate too, so that's always exciting 2 decades down the road.
I tried winning a Xbox One S from the Kellogs Cereal. I bought 60 boxes of cereal ( Cereal that I like) to try to win it. Never got that sticker.. But the Cereal was great. Ever since I seen the episode of the Big Bang Theory where Howard Wolowhitz was going to Space. I've been eating Floot Loops ever since.. And Special K. I still have the cereal box with win the Xbox One S console on it. I'm saving it. Maybe in 23 years I can sell it on Ebay.