Sony/Playstation has already taken steps for Steam support but they never went through with it fully. I made a post on reddit. Overall, I much rather see Microsoft have full Steam support.
Having full steam support and being able to use your game console like you are playing a PC game would be a deal breaker for many. Xbox has lost this generations console war and Microsoft will be limited to a niche market (Like Nintendo) for next-generation if they don’t secure a deal with Steam to bring full Steam support to a future console. Steam has already failed with their steam box. Both corporations need to come together. Xbox is all about easy backwards compatibility and cross platform play, all future exclusive titles will also be on PC. They must secure full Steam support for their future console, this will be essential to winning the console war and with PS5 to be a niche console like Nintendo.