Big disagree. I've been following this project since it's early days, and have made a few projects based on it. I haven't been bitten by any "inefficiencies" in such a way that'd make me give up the language. And at this very moment I'm working on what's essentially a Python REPL that can build and return Flet controls (as well as the traditional string result), making writing and running adhoc native "applets" fully on mobile a possibility (haven't seen anything else that does this).