Eminem is arrogant in ways that are entirely unjustifiable. He will side with and against rappers at his whim.
G-Eazy was befriended by Eminem to hit back at MGK and he called MGK a mumble-rapper while defending G-Eazy's honour against MGK's dissing of G on the side of having dissed Em. Eminem is a fucking two-faced guy but he will always be a powerhouse in the rap game that only Minaj and Vinnie Paz (you probably don't know who he is) can fuck with in terms of genuine rep and built-up thorough respect for what they broke the mould of and changed in the rap game; Minaj being not just a woman but such a powerful person due to her allies in the industry and Paz because he founded 3 labels/groups, 1 being he himself, and who is absolutely a founder and fundamental aspect to modern rap as we know it. He pioneered flow and lyricism in ways that none before him ever did and explored making beats that weren't hip-hop but still were gangster as fuck and pleasing to the eardrum.
Tech N9ne could arguably take Em on but he'd objectively lose because Tech's strategy is to fight 'around' enemies in the rap game and manoevre via other rivalries the enemy has. He did this with The Jokerr, even got the guy to release a 'sorry for dissing' song months later.
Tech N9ne isn't dead, Tech-9 is another person; a rapper-turned-commentator.