Savings accounts can be drawn with zero notice. They're essentially rolling overnight. A 10-year Treasury cannot be redeemed before 10 years. (It can be sold, though at the market's whim with respect to price.)
Note: I am not suggesting holding long term treasuries as a substitute for a savings account here, though a ladder of short term treasuries could be an alternative when conditions are favorable, like now.
The reference to "the market's whim with respect to price" means that if you bought $1000 of 10-year treasuries at the beginning of the year and you sell them now you'll get less than $900.
Duration risk matters a lot less with the shorter dates issues.