Currently Online 
Any company that threw it's hat into the ring would need to do several things. First off the system would need to be able to play PS5/XB Series 3rd party games with some level of competence greater than the Switch 2. Second, it would have to be a system that had a good price to power ratio. Third they would need to release 3-4 best selling peices of exclusive software a year. That's the most difficult part. If it were me, I would just aim for 60 FPS/1440p, simple shadow textures (instead of dynamically created), and no raytracing nonsense for my first party games. That way they would look great and be faster to create. Then I would include a way to upscale the games to 4K without using too much processing power.
Gain customers by making games $60 again and refusing to include Microtransactions or Online Fees. Make controllers that actually work for 30 years. No drift. Game-Key-Cards don't exist in actual storefronts like Wal-Mart or Bestbuy, but if you buy a game digitally you have the option of getting a free GKC or empty disc mailed to your house. That way all digital games can be resold or traded. You just have to deactivate your download and transfer the license from your account to your GKC or disc. Finally, I would include a heavy crossbuy feature where if you buy a game on our console and it's available on PC then as long as you still hold the license for that game on your console, then you can play it or transfer it to your PC.
Edit: Also bring back late-gen price cuts. A proper console should be $200 less than the launch price by year 5-6.
In other words get rid of all the anti-consumer BS that plagues modern videogames and focus on good exclusive content.
