I don't know about 50% but Citi group, Boeing, Ford and GM all did lay-offs in the 20-30% range in the last 20...

https://fortune.com/2015/09/20/biggest-corporate-layoffs/

HP did 30% in 2008 over multiple rounds.

Does anyone actually know how many Musk is laying off? (It seems there is an enormous amount of BS being claimed here, I heard 80%+ but with no reliable numbers, who knows)