Our current system works very well. It provides predictability and protects the rights of people. That's also why it's heavily biased against rapid changes. It's not _perfect_ for sure.
But the sortition-based systems are in general quite terrible exactly because they lack the feedback loops that keep societies stable. The main problem with the current administration, for example, is its disdain for these checks and balances and desire to move fast and break all the written and unwritten traditions.
There are also examples of failed sortition-based systems. I can give you the Soviet Union as one example. On paper, it was ruled by the Supreme Council ( https://en.wikipedia.org/wiki/Supreme_Soviet_of_the_Soviet_U... ). Its delegates were chosen mostly randomly from workers and then approved by a public vote. Yet it was a complete rubber-stamp organization with zero actual power.
Sortition made sure of that, people couldn't form reliable alliances and power-hungry people who could initiate real reforms almost never actually got chosen.
Oh it could be much, much worse. I can only imagine the harebrained ideas that would be popular. No more taxes of any kind. Free beer and cigarettes. Monthly checks of, I don't know, $10k a person.
At some point you need adults in the room(in mind, not age). Our system is obviously not great, but this is a way to make it much worse.
the problem with most politicians is that they're the sort of people who want to be politicians