> Good enough for what, exactly?

A FAANG-type eng job. IMO you're right that LC is not a predictor of success as a SWE, but it is for better or worse (I think worse) a gating factor for landing the job. We could talk for hours about how lazy it is to use LC-style problems as the gatekeeper, but the reality is that's what it is (ref: the guy who wrote Homebrew failing Google's interview loop).

OP seems to be conflating LC success with SWE success. LC is not what you need to be a successful and productive engineer, rather it's the prep you have to do if you want to play the FAANG interview game. What OP might be missing is that FAANG isn't the only show out there, and plenty of great non-FAANG companies don't interview this way.