LLVM seems to be a compile target with more mature implementations around it, so I figured LLVM would be a better assembly for the next generation EVM to run natively compared to WebAssembly which is a relatively new specification.
Webassembly(wasm) gives you more compatibility, portability, optimization than LLVM IR.
wasm makes transactions faster and thus creates a better environment for smart contracts(It allows you to write contracts in any LLVM languages that's the reason for moving forward from EVM to eWASM)
LLVM IR: 1) by default the IR is not portable >> the same program has different representations for different architectures or in different OS. 2) it is not stable >>it changes over time as optimization and language requirements change 3) LLVM’s binary format (bitcode) was designed for temporary on-disk serialization of the IR for link-time optimization, and not for stability or compressibility (although it does have some features for both of those).
WASM: It is stable, portable and bytecode are not temporary. you can optimise your code transaction is much faster