WHY IS THE SENATE DIRECTLY ELECTED? The only reason the senate is directly elect

WHY IS THE SENATE DIRECTLY ELECTED?
The only reason the senate is directly elected is because the state legislatures, in frozen conflict, would not and could not fill the open seats in the senate.
Now the senate is intended to serve as a proxy for the legislatures, just as the house is intended to serve as a proxy for the people, thus producing a competition that limited the folly of both legislature and people.
In reality there is little reason why the senate exists as a sitting body because governors could and probably should handle all senate business, thus restoring power to the sovereignty of the states. But the founders wisely considered the senate as a gate on the political whims of the governors. They set up competition that forced concurrency among the classes (not consensus in the population). So we are less victims of the fashions of parties and peoples than the rest of the western nations. The US is set up to produce concurrency not consensus. Which is a fact I’ve been working to explain now for a few years.
Likewise there is little reason why the house exists as a sitting body, because direct democracy or economic democracy could is easily produced with modern technology.
The only position useful to the nation is the presidency and even then, only because we lack a monarchy that can appoint a cabinet with the consent of the states.
Mostly this would kill party conflict at the federal level.
Cheers