Take down tesla why exactly? How exactly does that help?

Elongated Muskrat is currently sabotaging democracy. This is one of the few ways we can deliver consequences for his actions.

I would assume that changing the law is the course of action to prevent unauthorized access to critical systems.

You have a legalised form of corruption that has been crippling your justice systems for a while now that must be your primary concern.

You are thinking far to linearly. Think of this as a guerilla tactics to take advantage of media focus and what would happen if Musk crashed out.

Lets assume you managed to somehow bankrupt tesla. You effectively managed to stop one billionaire from using one of his many companies as a fast ATM. This does not solve the problem (billionaires affecting your governing system) in my perspective but merely mitigates a temporary symptom.