That dude's a meme chef [and imo a hack comedian] not a real chef. Yes MSG is good and underutilised in western cooking. No you don't need to add fistfuls to every dish. Other users are correct, about one fifth the equivalent in salt gives enough of an umami undertone without making everything taste like concentrated cheeto dust.

(tldr there's a reason why msg is referred to as a flavour enhancer and not a flavour. It should reinforce the savouriness of the dish not dominate it)