Let alone

Let alone is used after a statement, usually a negative one, to indicate that the statement is even more true of the person, thing, or situation that you are going to mention next; used to indicate that something is far less likely, possible, or suitable than something else already mentioned; ~은 물론이고, ~은 말할 것도 없이

• Number two is the brand and communications and getting consumers comfortable with our product, which is super important for the category, let alone for us as a brand and a company.
• That said, the most recent data available from Twitter via its half-yearly Twitter transparency report stated only 2.3% of all active Twitter accounts had MFA enabled. What it doesn’t say is that to enable MFA the user needs to (1) know and care that Twitter now offers it; (2) log into their Twitter account and explore the menus on their own to find the MFA settings (more → settings and privacy → security and account access → two-factor authentication); and (3) then follow the setup instructions. Given how difficult it is to even find, let alone follow, MFA instructions, is 2.3% adoption simply the fault of the users not caring about their security? (Link)

• He would never walk again let alone play golf.

• It is incredible that the 12-year-old managed to even reach the pedals, let alone drive the car.