Both Avengers and Guardians bombed so the IP alone is not a guarantee it'll be amazing.
People seem to be forgetting, or purposely ignoring, that Guardians bombed
because Avengers sucked and they were from the same publisher, so buyers just assumed Guardians was going to be a shitshow like Avengers and avoided it. It didn't bomb because it was a bad game, it bombed because
Avengers was a bad game and it got unfairly compared to it.
This thread would make people think all the super hero games are Avengers or Superman 64 levels of crap but that's hardly true. There is a wide range of quality, but most superhero games over the last two decades have been well received and sold fairly well.
Yes I would much rather we get new IP.
So would I. Quite the shame Microsoft hasn't bothered developing any and have painted themselves into a corner where the only way they can get new IP is to buy established studios like Bethesda or Activision/Blizzard. Especially when you stop and consider all the studios and IPs Microsoft owned during the OG Xbox and X360 era but pissed them all away as they obsessively focused on Gears/Halo/Forza/Fable (and then pissed away Fable, too).
Crimson Skies, Shadowrun, MechAssault, Viva Pinata, Kameo, Perfect Dark, Blinx, Banjo Kazooie, Quantum Redshift, Project Gotham Racing... the list goes on. Microsoft could have a Sony and Nintendo level stable of first party franchises across almost every genre if only they had simply invested in them.