I think the most interested party would be Xbox in acquiring Sega there would even be a bunch a game that could remain multiplatform such as Sonic, Persona and Megami Tense but all would release day 1 on Game Pass. There are two type of game missing from Xbox current portfolio Platformers and JRPG and Sega would serve both need.

If anyone wants to revive and fund Wild Arms and Skies of Arcadia it's Microsoft because they lack JRPG especially of that pedigree to attract a Japanese market. I think negotiation between Sega and Microsoft had a big roadblock because they did not want to acquire the Sega Arcade. Now that the arcade side been sold. It really seem like Sega is the next company that would get acquired.

I thing the big three all have the cash to acquire Sega and would be a big move for either one of them. But, I think Microsoft would benefit the most from the acquisition and really want a bigger presence in the Japanese market.

I mean, if Sega is as doomed as your post makes them out to be..... wouldn't that be more of a reason for someone to step in and buy them?

You make a good point, and I agree with you: Everyone would be better off if Nintend buys SEGA.

All 3 Nintendo, Microsoft, and Sony have enough cash on hand to buy Sega if they wanted to. (3.85 billion market cap) I would suggest Sega buys Nintendo and make the Dreamcast Switch but they don't have anywhere near the money to do so. Microsoft makes the most sense to try and build on the Japanese market, but both Nintendo and Sony make a lot of sense as well. Nintendo has always kept a great relationship with Sega over the years. If either Nintendo or Microsoft were to buy Sega or Atlus it would be a major blow to Sony who gets the elusive rights to mainline Persona games.

Team Ryu Ga Gotoku is also pretty good thing.

I think there also the fact that Sega would want to keep the Sega head quarters in Japan. If they got bought by Nintendo and Sony there would be a merger of companies. Only Microsoft would truly keep it as a subsidiary and let them operate as they always have been. Microsoft would also be the one willing to pay a higher premium. This deal would most likely be like Sony's Bungie deal that was just signed keeping everything multiplatform but give access to all of Sega game to come to Microsoft platform and more importantly to Game pass. 

I'd rather Sega not be bought by Nintendo, because I know all too well that Nintendo doesn't give a fuck about PC, and Sega makes quite a number of IP's for or showing up on the platform. Also Persona is starting to show up on PC, so Sega fan or not, the last thing you want to see is for Sega to sell Atlus to Nintendo and then have that IP taken away from other platforms instantly.

Just let Sega do it's own thing please, not everything and everyone needs to be bought by the big 3.

Honestly, it's surprising Nintendo or Sony didn't buy Atlus. And I'm pretty surprised none of the big three have bought Sega yet. Any one of them could easily afford it and make a lot of money.
But yes, I think Atlus is a smarter purchase than Sega as a whole. But again, Sony and Nintendo were dumb not to try (or seriously try) years ago.

No. SEGA can keep Atlus. SEGA can keep being 3rd party.