I sometimes wonder how the landscape of the video game industry would be is certain things were different. One major example is "what if Nintendo and Sony's partnership for the PlayStation as a SNES add-on still happened?" I think for one Nintendo likely wouldn't have suffered the third party problems they had in the mid to late 90s, as companies like Square more than likely would have kept franchises like Final Fantasy on Nintendo's platform.
But at the same time also remember the original PlayStation was an add-on, NOT a new console, and the Sega CD didn't really do the Genesis/Mega Drive any favors. Granted sure the PlayStation add-on probably had a higher chance of doing better if games like Final Fantasy and the like hit the add-on early in life, but then you start to wonder what if the PlayStation failed like the Sega CD. I think if that happened then all gaming companies would have been too reluctant to move on to the CD format as a primary storage method for games, and with Nintendo owning the PlayStation in this alternate history Sony likely would never come out with their own standalone console and thus we'd never have the PlayStation brand as it exists today.
Another big difference I see is Sega probably would have, at the very least, stayed in the console making business longer in this alternate timeline as they'd still only have Nintendo as their main competitor because Sony's working with Nintendo instead of against them. The Dreamcast probably would have been a much bigger success due to no PS2 to later take away all of its sales, but a Nintendo console likely would have still ultimately sold better thanks to higher third party support. I also think that as a result of Sega staying in the console business longer Microsoft would have never made Xbox since the Xbox was made by former Sega employees who left the company after making the Dreamcast and noticing the system just wasn't selling.