The IR is pretty messy but if you can see through the clutter the IR is much easier to read the flow of. There's a reason why we use SSA (although prior to mem2reg running you don't quite have it, but still)

Yes, exactly. Clang emitted IR especially has a lot of (C/C++)-specific junk. If you look past that clutter, it's not too bad.

I think the best way to learn to read IR is to look at super-minimal examples, and then you'll be able to tell which parts of larger IR files are relevant.

I'd say readability of dumped IR would be on par with dumped assembly from a compiler for readability, but hand-written LLVM IR has the potential to be quite a lot more readable than hand-written assembly