Big corporations are against capitalism?
Certainly some have a corrupt relationship with government, cadging for handouts,
eg, Tesla. But companies like Ford, GM, Apple, IBM, etc look very much to favor
& practice capitalism.
Even Tesla practices it, the unholy relationship with government notwithstanding.
Warren's proposal heads in the direction of the dictionary definition of "socialism",
by wresting much control of "the means of production" from the stockholders &
managers, & handing it to government & workers.
Note that I'm not claiming that this becomes "socialism", only that it moves things
in the direction of socialism.