Microsoft is a software company and that's what makes them have a capitalisation of 4$ Trillion.

Apparently they decided to be the biggest publisher on gaming software with the acquisition of Activision-Blizzard and Zenimax.

This makes sense. Do you believe that any other company will cover its spot on hardware sector or we will have a Sony/Nintendo/PC gaming sector in the future ?

Nope.

The only gaming company that is big enough to make a console is Electronic Arts i think.
Take Two cannot afford making its games exclusives as they output very few that rely on multiplatform sales like GTA.
Europe has no big Publishers except Ubisoft which is in bad shape and other Japanese developers aren't big enough i think.
The only other option is if Amazon/Google/Apple/Meta join the console race. They are the only ones that have a lot of money to burn.

I hope so. Because Sony sucks without competition.

Well they are not gone yet. We really dont know what their actual plans are for the future. Its hard to see it now, but maybe they will do something that really appeals to alot of gamers with the next Xbox.

I can't see another company spending so much money and time to build for years a new console ecosystem to compete with Sony.

Valve consoles are the closest we'll get, but I think that won't be direct competition either, but it's literally the only other company that could push something like it.

Any company having to start now, like Epic did to try to compete with Steam years ago is in such a disavantageous position that it hardly makes sense.

Microsoft themselves only did it for so many years to try to prevent Sony to spread into the PC space where their real money came from, and that was whe Sony was only in its second system.

Nowdays with the library people already built within Playstation anyone new trying to compete will be having a monumentous task, with loads of money bleeding for many years, to even try to do it.

So no, I don't expect it to happen.
It's easier for Sony to also drop it than for virtually anyone else to join and be able to compete.

Tencent?

PS2 era Sony is literally the best Sony. Their fumbles this gen had nothing to do with weak competition from Xbox.

OT:

The biggest publisher is Tencent. And no, no one is relacing old Microsoft/Xbox directly, but PC and eventually Nintendo are strong competitors of Sony.

Microsoft wasn't competition as much as they were a barrier to entry for other companies. Nobody wants to enter a console market as the fourth option.

As for who would replace them, it would be better if Xbox were just forcibly split from MS. Imagine an Xbox that tried to actually compete for once in 13 years. Hopefully that is what will happen. MS will attempt to push AI into Xbox, it will fail and then MS will sell the corpse to some other company that picks it up just for the brand recognition. And then said company pulls a Jaguar, but is successful. 

Tencent

East Asian market has untapped potential, they are heavily on PC gaming or not gaming at all

China alone can carry some hardware iteration until they finally can take off intentionally

Moreover China is much more sensitive to demand and specifications of growing and emergent markets like SEA, Latam and Middle west. Nintendo is the opposite their bussines strategy focus solely on rich markers and let ROW collecting dust, and Sony is increasingly following the same patterns with price increases across the board and no price localization of digital stores 

This can give them a competitive advantage to increase userbase enough to compete with Sony and Nintendo, even if they keep being a minor player in USA