Or you mean "big corpos"? Why does the size matter?
Or do you mean that those are unethical corporations?
So let's focus on preventing them from doing unethical things them.
In any case, we are living in society, so it is better to cooperate, and to no add but multiply our competences in order to create the future's solutions.
Living "by ourselves", all 8 billions of us, is the recipe for flash-burning through all of the planet's resources.
All of us just using wood for energy is just stupid and short-lived. Our "ancestors" lived on a much different planet and were much less many.
But let's not fall into the trap of hoping that violence can rescue us. That's the opposite of a solution. All the most devoid of ideas and of creativity, the most bloodthirsty, will win, and those are the least capable of well managing the planet in the future. (We are looking for how to prevent corporations to do unethical things, so we cannot at the same time call for guillotines.)
I'm not knocking capital and it's use in development I'm knocking usury, the immoral use of capital for things that don't take into account personal responsibility.
And violence is not maybe the best way, I don't practice or preach it, but its way we have chosen for the entirety of our past and it's probably the most "natural" way, thus I would argue inevitable. And ya no doubt it will suck for most of the planet, but the planet isn't going anywhere after all..just you and me, and I'm fine with that honestly.
And of course fighting against the idiotic far-right propaganda, largely responsible for the climate inaction.
Which by the way in the US has recently passed the stage of "inaction" to enter the realm of actively destroying the planet.