system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why do businesses have to pay tax? The owners are taxed anyway.

I'm aware that through the dividend imputation system (in Australia), any company tax paid is credited on the individual and therefore only counted once. 

And companies have been known to change locations, at least on paper, to seek the lowest tax rate (Ireland, various small island nations).

So why tax companies at all and not just tax the individual owners. It would save a bunch of work for the companies and the tax agency and remove the incentive for companies to relocate based on tax laws.
gpt
There are two main reasons. 

First, businesses provide benefits to employees that are hard to tax on the individual level. For example, it's hard to include the value of having a well-furnished private office on someone's personal income tax. If businesses are not taxed, these benefits escape taxation altogether, which actually undermines the idea of taxing personal income.

Second, it is much easier to tax businesses than individuals. Corporations have detailed account books whether they pay taxes or not, as these are crucial to the running of a business. Since they are semi-permanent entities existing in public, it is hard for them to dodge taxes in the way an individual can (by going into hiding, on death, etc.). The cost of administration becomes much lower.

Does point number 2 sound unfair? It is in a sense, but we see this in many taxes. Sales taxes have no social benefit, and indeed have negative social effects, because they overly burden the poor (who spend more of their income on consumption). But it's really easy to levy a sales tax compared to personal income. People have long argued for sales taxes to replace income taxes for this reason. Similarly, property taxes arose as a means to tax the wealthy, because it is much easier and less invasive to assess the value of real estate than it is to inquire into someone's income.

It's worth noting that in most countries, businesses do not pay taxes on the profits that they reinvest. So the tax does end up being primarily one on the owners' income, and not a drag on the actual business activity.