alt Hacker NewsParliament does have constitutional limits on it (for example, see timetabling powers or Erskine May), even if it can't pass acts that will bind future Parliaments. The constitution being (largely) unwritten and changeable doesn't mean it doesn't exist.
The result is substantially more democratic, as per the list above.
Please explain the constitutional limits to Parliament in more detail.
The result seems substantially more chaotic.
And then there is the fact that the entire legal frame work is based on The Crown. If the king or queen killed someone they would have to prosecute themselves. This is the exact opposite of democracy.