You’re correct that sequencing RNA/DNA is currently much cheaper and easier than directly sequencing proteins in a cell. But, knowing the sequence of a biomole

You’re correct that sequencing RNA/DNA is currently much cheaper and easier than directly sequencing proteins in a cell. But, knowing the sequence of a biomolecule is only a first step in understanding it’s function. By-and-large, we’ve had significantly more progress in describing functional domains (and therefore tying them to important biological processes) in proteins than we have in RNA.