Good! The west doesn't need to get any closer to being a corporatocracy.
But...that centuries of tradition means that companies, whether as a result of activists in meeting rooms or otherwise, get to make those decisions, and politicians don’t. By transferring that power from private actors deciding what ideas to use their own resources to transmit and promote to politicians, you would terminate that free speech tradition.
You’re appealing to centuries of free speech jurisprudence that constrains the actions of politicians. But the precise nature of that jurisprudence is to keep politicians as far away from the business of regulating speech as is possible.
Your proposal would purposefully involve politicians in the regulation of speech, contrary to that jurisprudence you point to. It is therefore not an internally consistent argument to point at the traditions you’re actively undermining as a reason why your actions will not have unintended consequences.