What does "eat away" mean, and how's difference from just "eat"?
"Eat away" is a colloquial expression meaning to erode, consume, gradually damage, or deplete something. It involves the verb "eat" (meaning to consume something), but in this context, is not used in reference to food. In this video, the speaker has used "higher costs eat away at profits" to mean that "higher costs deplete/reduce profits." Ex: The waves have eaten away at the coast, causing it to shrink over time. Ex: The guilt has eaten away at Stacey. She has many sleepless nights. (The guilt has gradually damaged/harmed Stacey.)