Not only is it not getting simpler the tax code seems to keep growing as more exceptions and exemptions get added. I guess it's like so many legacy code bases that just keep growing with lots of patches for special cases.
According to the Public Law 117-154(06/23/2022), the U.S. Tax Code is 6,871 pages. When you include the federal tax regulations and the official tax guidance, the number of pages raises to approximately 75,000. This zip file (pdf) is 181MB [0].