How do you allocate that? Surely you can't give anyone who asks the same amount. So you favour parties which are already entrenched. Of course that has quite a few upsides but it doesn't seem like an inherently democratic system.

In worst (of course not unavoidable) you also might end up with indirect equivalent of what your re trying to ban, e.g. private media companies with a lot of resources that are biased towards certain candidates influencing public opinion (without crossing the legal boundaries) or those already in power using the state media to do the same.

e.g. in Hungary most funding comes from the government. How did that work out for them?