As we previously reported, billionaire Glen Taylor -- who has owned the team since 1995 -- began listening to offers to sell the team back in July 2020 ... with KG "seriously interested" in taking over the reins with a group of investors.

But, that dream is officially dead ... with Garnett sounding off on the outcome in a fiery Instagram post.

"Sooo just got the news that this process in trying to acquire the TWOLVES IS OVER for me n my group," KG said. "Thx Glen for being yourself n what I Kno you to be!!! GOOD LUCK n aww the best with WHAT WE BUILT."

Remember, KG -- easily the best player in franchise history -- HATED Taylor for years ... but extended an olive branch in hopes of working together to rebuild the organization.

But, that strategy ultimately didn't work ... and Garnett says he's "not hurt, just disappointed" in losing out on the opportunity.

"Crazy that some of these players that helped build these fuxin Franchises like a home but can never own them, only rent them," he said.

"GTFOH ISHHH IS A JOKE ... Fux em doe ... your loss."

Garnett seems to be holding out hope on being an owner in the future, however ... listing cities like Las Vegas and Seattle as possibilities.

As for the Wolves?? He's taking the Chris Brown approach.