Why don't governments ban businesses from passing tax costs onto their customers? So, after a bit of discussion in the comments of this question on the Politics SE, I figured I'd post it here:
One of the arguments against taxing large businesses is that they'll just pass the costs on to their customers, effectively raising inflation and harming the working class, or cut costs by making employees redundant.
Why don't countries pass laws imposing taxes and legally mandating that companies are forbidden from doing either of these things, and that it must be paid directly out of their profit and/or owners' equity? This might possibly take the form of the government mandating that all businesses over a certain size must issue X% of their shares to the government without granting the government voting rights, so that the government owns X% of all of their profits.
Are there any countries who have done anything like this? How did it work for them, if so?
I don't see how the government taking X% of a business's profits is stopping the business from increasing prices (or is this just the penalty in the enforcement clause?), so I am going ignore that part.

What you are describing is essentially setting prices, determining what prices a business can and cannot set. (If you merely prohibited passing on costs, the business would claim that they are not doing this, they merely happen to be raising prices because of other reasons.)
This usually means a planned economy rather then a market based one, as the most important function of the market is to set the prices. Allowing the market to do this results in all sorts of nice things: it balances supply and demand, provides incentives for innovation, etc.
To some extent even market based economies engage in price setting. Sometime governments set price ceilings on some products. The usual reasons behind this are

Fairness: at the lower price demand will outstrip supply (in fact the low price will likely diminish supply), but everyone will have a chance of buying some of this good, not just the wealthy who could afford the higher equilibrium prices. (See rent control.) The dynamic effects are assumed to be negative: the lower price will disincentivize future investment.
Non-competitive markets: if the market is not functioning properly, e.g., someone has a monopoly on the good, price setting may actually increase the quantity sold and have a positive effect on net welfare.
Anti-price gouging: if there is a short term demand spike and supply is strongly inelastic, prices may skyrocket in a given market. (Such was the case in some good markets at the start of the Covid-19 pandemic.) In this case, a price ceiling may transfer welfare from producers to consumers without significant welfare loss (if supply is really strongly inelastic). The term &quot;anti-price gouging&quot; is somewhat unfortunate as it is emotional with sensationalistic overtones.
There are also non-economic reasons: such a measure may be politically popular, even when there are downsides, as these are not immediately visible.

Recommended further reading:
REVIEW OF ECONOMIC THEORIES OF REGULATION