Usually they only comply by suing them, after nagging them for years…

Everyone is free to edit, compile and use LGPL licensed code however you want on your PC. A DMCA can’t stop that, so it won’t make sense for someone to think that. At the time you share software (as a binary which used that LPGL licensed code, or the code itself) is when you are legally compelled to follow the license (hosting code on github).

But sharing code is when a license like LGPL really has an effect in what you must do to comply…

FFmpeg has faced some criticism for this DMCA takedown

Such as?