One of the reasons why existing systems tend to crash and shatter before they can be reformed is that the people with the power to change a system benefit from the status quo.
Plenty of legislators have vowed to simplify taxes. What’s one of the biggest levers of power that legislators have and use? The power to write tax law that favors some over others. A flat tax with almost no line-item deductions is anathema to virtually every lobbyist.
I’m sure you can think of other examples where change is slow-to-never because everyone has figured out how to benefit from the status quo. Health care. Judicial systems. The local school system. The family reunion.
Another reason why big changes are difficult is that someone, inevitably, has to say, “I was wrong about X and we should change it.” That’s a big ask.
Ptolemy of Alexandria popularized the idea that the earth was the center of the universe, and everything revolved around it. Practically everyone thought this way for about 1400 years until Nicolaus Copernicus convinced people that the sun was the center of the solar system. (Sorry, Aristarchus of Samos, most people never heard of you, even if you beat Copernicus by 900 years.) Many people were still struggling with heliocentrism for about a century after Copernicus – it was simply hard to believe smart people were so wrong.
There’s a similar story about canals on Mars. Right up to 1965 when Mariner 4 did a close fly-by, the conventional thinking was a civilization existed on Mars because of all the straight lines you could see in telescopes of the day.
I’m sure there is something we’ll discover in the future which unseats something we all believe firmly today, and it will be hard to accept.