This is by design. Governmental systems are "captured" by special interests and made intentionally obtuse and complex as a barrier to entry. Lawyers and judges are a guild that works to make the law complex and extract rents from the productive economy. Over 1/3 of the U.S. Congress are attorneys as well.
I honestly don't think there is such a malicious intent behind it. Perhaps in some small instances.
Generally, the fact of the matter is simply that law is highly complex and the way it evolves is almost always by creating new laws, not getting rid of old ones. That's unfortunate obviously, but just like you don't just rewrite the Linux kernel, you can't just reset the legal foundation.
Some, and maybe most, of the complexity is organic. But there are specific instances, like the tax code, that have been kept intentionally complex at the bequest of special interest groups.
And of course, laws are made mostly by lawyers. So they don't have much of an incentive to change things.
