Do I really need a laptop sleeve if my backpack already has a padded compartment?

Across the travel-focused subreddits we read (notably r/onebag), the consensus is yes for travel: a sleeve protects against scuffs from sand, keys, and other gunk that ends up in a backpack compartment, and it lets you pull the laptop out without unpacking everything at TSA. For pure desk-to-desk commutes it matters less.