All taxes are avoided (or illegally evaded) to some degree, and the most taxed (i.e. the wealthiest people and firms) will always have the largest incentive to avoid taxes. To reduce the incentive to avoid taxes, countries often tax capital (or labor) at multiple stages but with lower rates (e.g. a corporate tax, dividend tax, and sales tax). As you point out, the corporate tax is redundant to other forms of taxation, but the redundancy lowers overall taxation rates and hence tax avoidance. So it's a feature not a bug of modern taxation.

Some interesting alternatives to corporate taxation have been proposed[1][2], and I think they merit consideration for their potential to remove disincentives to invest or hire labor. I personally like Michael Pettis's argument that continued economic growth depends on increasing economic demand through redistributing wealth from capital (or more generally the wealthy) to labor [3], so I am skeptical of reforms that stop taxing capital.

[1] https://cdn.americanprogress.org/wp-content/uploads/issues/2... [2] https://taxfoundation.org/value-added-tax-revenue-neutral-al... [3] https://foreignpolicy.com/2020/09/29/capital-flow-united-sta...