Is modern day Disney only successful, because they are leeching off of the success of Marvel?

Honestly, Disney themselves are shit.
They ruined Star Wars with their tepid-at-best new trilogy and the terrible standalone films, and they are flooding the cinemas with cynical cash-grab live-action remakes.
And seriously, the only reason that the MCU was the success that it was, is that they ‘graciously’ let Feige be in charge of it.
That this is true, you can see by the fact that they nearly fucked up Guardians 3 by firing Gunn over some triviality, and now fucking up the Spiderman deal with Sony, by making them an “offer” that Sony simply can not afford to agree to, messing up the canon that the MCU has built up so far.
I think that without Marvel’s success, and their association with Disney, their live-action remakes would all rightfully tank.