One problem I see is even in representational democracy (I'll use the Westminster system for concreteness) we get a lot of indirection leading to policies people don't actually want. Even more indirection is bad.

Assume members of parliament are chosen fairly (popular vote approximates number of seats etc). The winning party (or parties) form a cabinet - their own little hierarchy. What we tend to see is a majority of cabinet members voting in cabinet for a policy, a majority of their caucus voting to support their policy (relying on cabinet solidarity to get the numbers across the line), then a majority of parliament passing a bill (using the solidarity of the party to get it across the line). The agenda may have been set by just a few parliamentarians (say just 9 out 17 cabinet members in a parliament of ~100) and an unpolular policy comes to pass.

I'd fear having local representatives choosing state representatives choosing federal representatives would have even worse outcomes in terms of representing the individuals at the "bottom" of this process. There is a reason representatives are voted for directly at each level of governments in our democracies - this wasn't a "simplification" it was a deliberate choice by our forebearers who had seen how politics shakes out in practice.